Ash's Greninja

Ash's Greninja (Japanese: サトシのゲッコウガ Satoshi's Gekkouga) is the first Pokémon that Ash obtained in the Kalos region.

History
Greninja's early life was first seen in a flashback in Cloudy Fate, Bright Future!. As a Froakie, it hatched from an Egg and lived its life alongside other Froakie in a pond. While the other Froakie spent their time playing and dancing, it spent most of its time away from the others training itself. Due to this, it was seen as a disturbance to the group and was attacked. A Nurse Joy healed Froakie and gave it to Professor Sycamore to be given away as a starter Pokémon, new Pokémon Pokémon Trainers could choose. It then learned that it could only get strong with a Trainer it trusted and became very selective of its Trainer. Because of this, Froakie had gone through several Trainers, but came back to Sycamore after either leaving them or being returned for being disobedient.

It first saw Ash when he was kicked out of the Prism Tower in Kalos, Where Dreams and Adventures Begin!. It continued to observe the gang until Team Rocket intervened in Ash and Clemont's friendly Pokémon battle. It volunteered to help out by successfully using its Frubbles to counter Jessie's Wobbuffet, but ended up receiving quite a bit of damage during the encounter. Ash then decided to take it to Sycamore's lab, where it was treated and restored to full health. Upon asking about its Trainer, Sycamore told Ash that its Trainer had called to give Froakie back.

Later on, Team Rocket attempted to use a ring-type device against Froakie, but the lab's resident Garchomp got caught in the middle instead, causing her to go on a rampage after the machine malfunctioned. Ash, along with his Pikachu and newly befriended Froakie, headed out to rescue Garchomp. In order to prevent her from falling down the Prism Tower, Froakie used its Frubbles on Garchomp's feet and Pikachu broke the device using Iron Tail.

While leaving Professor Sycamore's laboratory the next day, Froakie threw a chunk of its Frubbles in Ash's face in order to get his attention. It was standing alongside a Poké Ball on the floor in front of it, expressing its desire to join his party. Froakie then happily pressed the Poké Ball's button and was caught.

With Ash
In A Battle of Aerial Mobility!, Froakie was introduced to Professor Oak, who was fascinated by the Bubble Frog Pokémon. For most of the trip on Route 4, Froakie was seen outside of its Poké Ball. After a wild Fletchling took a Berry that Bonnie was going to give to a Dedenne, Froakie stubbornly attempted to fight Fletchling, only to lose. After Ash learned that it was only trying to get payback at Fletchling for making Bonnie sad, Ash and Froakie challenged Fletchling to one final battle, by climbing the rocks to match Fletchling's speed, although Fletchling escaped from Ash's Poké Ball once, Froakie later defeated it, which ended in both its defeat and catch.

In Kindergarten Chaos!, Froakie battled Penelope's Sylveon. Froakie started off with Bubble, but Sylveon overwhelmed the attack with Fairy Wind, knocking Froakie into a tree. Froakie then dodged a Moonblast and kicked several falling apples from the tree at Sylveon. Sylveon knocked the apples away with its feelers, but this left it vulnerable to a powerful Water Pulse. As Froakie was about to finish Sylveon off, Sylveon infatuated it with Attractand defeated it with a Draining Kiss. After the group had arrived at the kindergarten where Penelope worked, Froakie was embarrassed for a while after its loss and stood alone, while the other Pokémon played with the kids. When Team Rocket appeared and stole Pikachu and Sylveon, Froakie and Randall, one of the kids, were accidentally left trapped in Team Rocket's truck amidst the chaos. Later, when Ash entered the truck, the three worked together to break the glass containers holding Pikachu and Sylveon, while also helping Randall get over his fear for Pokémon in the process. Froakie and Pikachu then defeated Team Rocket, blasting them off. Afterwards, Froakie and Randall gave each other a fist bump as a sign of their new friendship, before the group said goodbye to everyone at the kindergarten.

In A Rush of Ninja Wisdom!, Froakie battled Sanpei's Frogadier. Froakie started off with Bubble, but Frogadier easily dodged the attack. Froakie then chased after Frogadier while using Pound, but wasn't able to land a hit due to Frogadier's great speed. Froakie then launched a Water Pulse at Frogadier, but it protected itself with Smokescreen and disappeared. Froakie, however, sensed something behind a tree and fired a Water Pulse at it, only to have hit a decoy. Frogadier then appeared from the nearby pond and attacked with Bubble. Froakie countered with its own Bubble, but got overpowered. After its Water Pulse was overpowered by Frogadier's, Froakie used Water Pulse once more. Frogadier, however, easily dodged it using Quick Attack and unable to keep up with Frogadier's moves, Froakie was hit hard. Froakie, however, refused to give up and wanted to continue the battle. As Frogadier used Quick Attack to finish Froakie off, Sanpei noticed Froakie's exhaustion and saved it before it got hit, ending the battle with Sanpei as the winner. After seeing Frogadier's Quick Attack, Ash wanted to teach Froakie Quick Attack with help of Sanpei. After lots of training Froakie still wasn't able to perfect Quick Attack. Suddenly Team Rocket attacked the group and caught Pikachu and Frogadier. Thanks to its training, Froakie managed to learn Double Team and used it to free Pikachu and Frogadier and blasted them off along with Frogadier using a double Water Pulse.

In An Undersea Place to Call Home!, Froakie, in order to save itself and a Skrelp from a whirlpool, jumped on boxes and debris to escape from the whirlpool and reach safety. This gave Ash the idea for the Rock Tomb Climb.

In Climbing the Walls!, Ash used Froakie as his first Pokémon in his Cyllage Gym Battle against Grant. Froakie went up against his Onix. Froakie launched a Water Pulse whilst Onix used Flash Cannon, with only Flash Cannon hitting. Froakie tried to get close to Onix to climb up its body, but Grant anticipated this and he had the Rock Snake Pokémon use Rock Polish to increase its Speed. Ash had a plan though and had Froakie use Double Team to circle Onix. Onix then used its signature move Rock Tomb to destroy the copies, but Froakie used this moment to perform its newly learned technique Rock Tomb Climb to climb onto the falling rocks. After reaching the top, Froakie used Water Pulse which dealt major damage to Onix. After narrowly dodging an Iron Tail, it climbed up Onix's large body and defeated it with Water Pulse. It then went up against Grant's last Pokémon, Tyrunt. Froakie immediately used Double Team while Tyrunt used Rock Tomb. Both Froakie and its copies were again able to jump on the rocks and they launched a barrage of Bubble attacks. However, the Royal Heir Pokémon jumped high and used Draco Meteor, destroying the copies and knocking Froakie out.

In The Forest Champion!, Froakie was used to battle a wild Hawlucha Ash had befriended when he did not want to use Pikachu. Due to Hawlucha's aerial mobility and speed it easily dodged Froakie's Water Pulse, but Froakie then used Double Team to counter Hawlucha's High Jump Kick, causing it to miss and cause Hawlucha to take recoil damage. Froakie then climbed rocks in an attempt to match Hawlucha's aerial speed, but failed, causing it to fall in the water. Afterwards it used a Double Team - Pound combination in an attempt to hit Hawlucha, but Hawlucha used its speed and climbed up the tree and dodged the attacks. After landing on the ground, Hawlucha used Flying Press, which Froakie countered with Pound at the last minute, causing a collision which knocked out both Pokémon. This ended the battle in a draw. Later Froakie was seen when Ash caught Hawlucha.

Froakie would later conflict with Hawlucha in Forging Forest Friendships!. In the wake of learning Cut, Ash and Clemont decided to have a battle where Froakie and Hawlucha battled against Chespinand Bunnelby. Ash commanded Hawlucha to use Karate Chop to counter Bunnelby's Mud Shot, but Froakie used Water Pulse on Bunnelby. This angered Hawlucha since Froakie, and not itself, had hit Bunnelby. The dispute later escalated causing them to be separated by Ash. In an attempt to diffuse the tension, Ash decided to try and train the two into using a new move called "Super Flying Cut". During their training, Ash got kidnapped by a wild Trevenant and both Froakie and Hawlucha got separated from the rest of the group. After finding Ash's hat, the two resolved their differences and sought to find their trainer. After finding him, they battled Team Rocket, overcoming their Pokémon with their new special move and blasting them off. Froakie and Hawlucha settled their argument and gave each other a fist bump, solidifying their new friendship.

In Summer of Discovery!, Froakie had a "first-touch battle" against Tierno's Squirtle. Froakie started off with a Water Pulse, but Squirtle dodged it easily. Ash then commanded Froakie to use Water Pulse again, but Squirtle was too fast. It dodged again and ran to Froakie. Squirtle touched Froakie, causing Froakie to lose.

In A Stealthy Challenge!, Froakie was training with Ash and Pikachu until Bonnie noticed Sanpei in the water, and went to rescue him and his Greninja, who were previously attacked by Saizo and his Barbaracle. After thwarting another attack, the group decided to aid Sanpei in finding a mansion so he could deliver a secret document given to him by his mentor. After saving Clemont from falling via his Frubbles and then being separated from Clemont, Bonnie and Serena in a cave full of Golbat, Froakie and Greninja encountered Saizo once more in a rematch but neither their joint attacks or the involvement of Pikachu gave them the upper hand. After being trapped in some rocks by Barbaracle's Mud-Slap, which had also blinded Pikachu and Greninja, Froakie broke free and evolved into a Frogadier, managing to weaken the Collective Pokémon using its newly-learned Aerial Ace before Saizo fled the battle. After reaching the mansion, it was revealed that Saizo was in fact Sanpei's mentor, who had been testing his student and that the document was actually blank. Frogadier and Greninja had a battle at the end of the episode, though the outcome is unknown.

In The Green, Green Grass Types of Home!, Ash used Frogadier as his third and final Pokémon in his Coumarine Gym Battle against Ramos. Despite being at a type disadvantage, it went up against Weepinbell which had already defeated Fletchinder and Hawlucha. Frogadier used Water Pulse, but this was dodged. It then used Double Team and circled around Weepinbell. Weepinbell, however, used its hearing to sense the real Frogadier and used Grass Knot, tripping up Frogadier and removing the copies. Weepinbell then used Razor Leaf, but Frogadier countered with its Water Pulse. Weepinbell used Poison Powder, but Frogadier used its Frubbles to cover its mouth, preventing itself from becoming poisoned. It then used Double Team to circle Weepinbell again. Weepinbell, went for Grass Knot again, but this time Frogadier used Aerial Ace, destroying the Grass Knot and using the attack to defeat the Flycatcher Pokémon. It then went up against Ramos's last Pokémon, his Gogoat. Frogadier used Water Pulse, but it was blocked by Vine Whip. When Frogadier used Double Team, Gogoat countered with Vine Whip again, destroying all the copies and hitting the real Frogadier hard. Gogoat then used Razor Leaf around itself, hiding itself. Frogadier destroyed the leaves with Aerial Ace, but Gogoat had jumped up high and redirected the leaves to hit Frogadier hard. Frogadier then used Double Team which was destroyed by Leech Seed. Frogadier, however, managed to avoid it and then hit Gogoat with Aerial Ace. Gogoat was able to withstand the hit and used Horn Leech, dealing damage and having recovering some of the damage it took. It then used Leech Seed on Frogadier, trapping it while draining Frogadier's health. Gogoat then used Razor Leaf, circling around Frogadier while launching leaves at it. This made neither Ash nor Frogadier able to see Gogoat. Then Ash remembered the advice that Ramos told him - that getting flustered would only make matters worse, and that if he kept a level head he'd be able to see the important things - and had Frogadier listen for the sounds of Gogoat's movements. After getting hit by multiple leaves, it managed to sense Gogoat and cut through the Razor Leaf and did major damage with Aerial Ace before using Double Team. Though the Mount Pokémon took out the copies with Vine Whip, this gave Frogadier an opening. It hit Gogoat with Water Pulse and knocked it out, winning Ash the battle and earning him the Plant Badge.

In A Fashionable Battle!, Ash used Frogadier and Hawlucha for his Double Battle against Sawyer, where they went up against Sawyer's Treecko and Bagon. After Hawlucha and Bagon battled, Treecko used Leech Seed on Hawlucha which it managed to dodge. Bagon then tried hitting Hawlucha with Fire Fang, but it got blocked by Frogadier's Water Pulse. Later Frogadier used its speedy movements to dodge Treecko's Bullet Seed. As Treecko used another Bullet Seed on Frogadier, Frogadier seemingly disappeared just before the attack hit. It reappeared in the air and Treecko tried stopping Frogadier using Bullet Seed. Frogadier cut through the seeds using Cut repeatedly and defeated Treecko. Ash and Sawyer then prepared to resume their battle, but they got interrupted by the commotion caused by Valerie's Fashion Show.

In Rivals: Today and Tomorrow!, Ash used Frogadier as his third Pokémon in his three versus three battle against Sawyer. It went up against Treecko, despite the type-disadvantage. Frogadier hit Treecko with a super-effective speedy Aerial Ace, surprising Sawyer. Treecko then hit Frogadier with Bullet Seed. Treecko kept using Bullet Seed while moving, which Frogadier struggled to dodge. Treecko then used Agility in an attempt to outspeed it, but Frogadier was able to stop it by hitting Treecko with a Water Pulse. Agitated, Treecko suddenly evolved into Grovyle, learning Leaf Blade in the process. Frogadier used Double Team, of which Leaf Blade destroyed the copies. This, however, left Grovyle open for a surprise Aerial Ace from behind by Frogadier. After dodging more Leaf Blades, Frogadier used Cut as Grovyle used Leaf Blade which cancelled each other out. Grovyle then used its jumping abilities to jump in the air and use Bullet Seed, but it was countered by Water Pulse. This created smoke which allowed Frogadier to get into the air and counter attack with Water Pulse from behind, defeating the Wood Gecko Pokémon. After the battle, both Frogadier and Grovyle were impressed with the other's abilities and developed a rivalry with each other.

In Cloudy Fate, Bright Future!, it was used to battle Carrie's Sigilyph and Sableye along with Pikachu. After it had hit Sableye with Water Pulse, it got hit by a Shadow Claw. It then countered Sableye's Power Gem with Water Pulse and then defeated Sableye with Aerial Ace. After the misunderstanding had been solved, the group followed Olympia to the Anistar Gym. There, Olympia revealed Frogadier's past and revealed it would gain great power.

In All Eyes on the Future!, Frogadier was used along with Talonflame in a Double Battle against Olympia's two Meowstic at the Anistar Gym. After Olympia's Meowstic used a Helping Hand-boosted Future Sight, Frogadier and Talonflame headed in for the attack. Both Meowstic simply dodged the attacks and began levitating. Ash then had Frogadier attack the female Meowstic with Water Pulse. Water Pulse's damage, however, was reduced as the male used Light Screen to protect his partner from the attack. Frogadier then caught Talonflame, who was falling down after getting hit. Both Meowstic then fired off their Psyshock, which kept following their targets due to the female Meowstic's Ability Keen Eye, and were able to hit their opponents. As Frogadier and Talonflame stood up and were about to counterattack, wormholes appeared and Future Sight struck Talonflame, knocking it into Frogadier. Ash then came up with a strategy to have Pikachu keep track of the time it took for Future Sight to hit its mark. Ash then had Talonflame use Brave Bird and Frogadier use Double Team to cover Talonflame. After the female Meowstic wiped the clones out with Dark Pulse, its Dark Pulse was cancelled out by Frogadier's Cut, giving Talonflame the chance to hit her hard with Brave Bird. She, however, immediately recovered and launched a Thunder Wave at Talonflame, but Frogadier jumped in and took the attack, paralyzing it. Frogadier then aided Talonflame, who charged in for the attack, by blocking the Meowstic's Psyshock, giving Talonflame the chance to hit the male Meowstic hard. Ash then had Frogadier attack with Aerial Ace, but it was unable to execute it due to its paralysis, leaving it vulnerable to a Dark Pulse. After Future Sight was used again, Frogadier was carried by Talonflame and both charged towards the Meowstic. The Psychic-type Pokémon attacked with Psyshock and Dark Pulse, which kept following their marks again. Talonflame, however, led the attack towards the Meowstic and flew off at the last moment, causing them to get hit by their own attacks. Frogadier and Talonflame then grabbed onto the Meowstic. Thanks to Pikachu, they were able to let them go at the moment Future Sight was executed, causing it to hit Meowstic instead. It was then saved from Psyshock by Talonflame, who used Flame Charge to shield itself and Frogadier from Meowstic's attacks. As Talonflame knocked the female Meowstic out with Flame Charge, Frogadier prepared to defeat the male with Water Pulse. Due to its paralysis, however, it couldn't launch the attack, giving Meowstic the chance to fire off a Psyshock. Despite struggling to block the attack with the Water Pulse between its hands, Frogadier managed to overpower Psyshock, thanks to Ash's words of encouragement, and knocked Meowstic out. This gave Ash the victory, earning him the Psychic Badge.

In The Legend of the Ninja Hero!, Frogadier was seen training with Ash. It then met up with Sanpei and his Greninja again, who took the group to his hometown, the Ninja Village. Frogadier watched the battle between Sanpei's Greninja and Nihei's Venusaur with great interest and was shocked when Greninja was beaten. It then followed Ash and his friends and saw the shrine dedicated to the Hero Greninja. When the village was attacked, Frogadier and Ash along with Sanpei and Greninja chased after the kidnappers of Hanzo, the village elder, but were confronted by Heidayu and his Bisharp. The attack on the village continued in the next episode, in which Frogadier, along with Pikachu and Sanpei's Greninja were ready to face Heidayu's Bisharp. Bisharp easily overcame their combined efforts, but was defeated by the returning Saizo and his Barbaracle.

Later Frogadier joined Pikachu and Sanpei's Greninja in a rematch with Bisharp, but still struggled against the Sword Blade Pokémon. While the three Pokémon struggled to stand from Bisharp's Snarl, Heidayu ordered Bisharp to finish Pikachu with Shadow Claw. At the last moment, Frogadier managed to get up and jump in front of Pikachu to protect him, causing it to evolve into Greninja and learn Water Shuriken. Following its evolution, Greninja managed to pose a larger threat to Bisharp with its new powerful attack. Hearing Ash's words of encouragement, Greninja mysteriously transformed into a new form known as Ash-Greninja. With its new power, Greninja easily managed to knock Bisharp out with a powerful Cut before the torrent of water surrounding it dissipated and Greninja reverted to its normal form, leaving Ash confused over what had just happened. After the Ninja Army was defeated, Greninja bade Sanpei and his Greninja farewell as Ash and his friends left the village to continue their journey.

In Meeting at Terminus Cave!, Greninja was used by Ash to retrieve Squishy, who was captured by Team Rocket at the time. Greninja quickly retrieved it and returned it to Bonnie, after easily dodging the Cross Poison and the Stone Edge fired at it by Celosia's Drapion and Bryony's Bisharp, respectively. After Squishy defeated Team Flare's Pokémon and ran away, Greninja battled Celosia's Manectricand Bryony's Liepard, who chased after Squishy. Greninja blocked Liepard's Shadow Claw with Cut, but while locked in combat with Liepard, it got hit by Manectric's Thunderbolt. Greninja refused to give up, however, and transformed to its Ash-Greninja form. It easily beat back Manectric and Liepard with its great speed and power, forcing Team Flare to retreat. During the battle it was shown that Ash and Greninja share each others pain and exhaustion while Greninja was in its Ash-Greninja form. Afterwards, Greninja and Ash fell to their knees in exhaustion.

In A Meeting of Two Journeys!, Greninja was first used to battle Sawyer's Sceptile. It first countered Bullet Seed with Water Shuriken and then attacked with Cut, which was dodged. After its Aerial Ace clashed with Sceptile's Leaf Blade, Greninja was hit by a Dragon Pulse. Sceptile then trapped Greninja with Leaf Storm and then smashed it to the ground, dealing lots of damage. Greninja, however, was still able to stand and easily defeated Sceptile with Aerial Ace upon transforming into Ash-Greninja. Its transformation was noticed by Alain, who was passing by.

The next day, Alain requested a battle with Greninja, to which Ash agreed. Greninja fought Alain's Charizard, which was able to hold the upper hand despite a type-disadvantage. The match started with Charizard countering Greninja's Water Shuriken with Dragon Claw, and dodging Greninja's attempts to hit it with Cut. It retaliated with Flamethrower, causing Greninja some damage. Afterwards Charizard Mega Evolved and attacked with Dragon Claw, but Greninja countered with Cut. Greninja attempted to confuse Charizard with Double Team, but the Flame Pokémon countered by destroying all the copies with Flamethrower. Greninja then emerged from the smoke and attempted to hit Charizard with a surprise Aerial Ace, but the latter revealed its newly learned Thunder Punch and knocked Greninja away. Greninja tried to retaliate with Water Shuriken, but Charizard proved to be faster and hit it with a second Thunder Punch. When the battle seemed to be over, Greninja transformed into Ash-Greninja and managed get a good hit on Charizard with Aerial Ace. Charizard, however, quickly recovered and used Thunder Punch, which Greninja blocked with Cut. Charizard was then able to break through Cut and finished Greninja off with Blast Burn.

In The Synchronicity Test!, Clemont had developed an invention to monitor Ash and Greninja's pulse in order to get to know more about Greninja's transformation into Ash-Greninja. Greninja was sent out to spar with Clemont's Luxray to try and trigger the transformation. Luxray started the battle by powering up his Electric-type moves using Electric Terrain. Greninja then used Cut, but Luxray countered with Thunder Fang, pushing the Ninja Pokémon back. Greninja then used Double Team and although Luxray destroyed all copies with Wild Charge, it managed to strike the Gleam Eyes Pokémon with a surprise Aerial Ace. After clashing with Cut and Thunder Fang again the battle was stopped, since both Pokémon were tired and Greninja's transformation still hadn't taken place.

After Alain showed up, he and Ash agreed to have a rematch, with Greninja battling Alain's Charizard once more. Like in their previous battle, Greninja opened with a Water Shuriken. Charizard skillfully dodged the incoming shurikens and retaliated with Dragon Claw, hitting Greninja hard. Greninja, however, quickly recovered and used Double Team which proved useless against Charizard's Flamethrower. This, however, proved to be a diversion that allowed Greninja to strike Charizard from behind with Cut. After Charizard Mega Evolved, Greninja showed the full extent of its improvement by overpowering Charizard's Thunder Punch and kicking it in the stomach with Aerial Ace. It then attacked with Cut, but Charizard grabbed its attack and hit it with a close-range Flamethrower. It then tried to stop Charizard with Water Shuriken, but the Flame Pokémon dodged the attack once again and proceeded to hit Greninja with a powerful Thunder Punch. This, however, allowed Greninja to successfully transform into Ash-Greninja. With its increased power, Greninja was able to match Charizard in combat. After its Cut was dodged, it was able to block Charizard's Flamethrower with Cut. Greninja then jumped in the air to avoid Charizard's Thunder Punch and struck it from above with Aerial Ace. After a collision between Cut and Dragon Claw, Greninja managed to take a hit from another Dragon Claw before dealing serious damage to Charizard with an immediate Cut. The battle was called off when Ash collapsed from exhaustion. When Ash regained consciousness, Ash realized that he and Greninja would have to be more careful in using Greninja's special form and vowed to train harder in order to perfect it.

Their training was seen in Championing a Research Battle!, where the two raced through a forest in order to boost their stamina. When Diantha arrived to inform Ash and his friends about Zygarde, she also requested a battle with Ash and Greninja after hearing of Greninja's special power. Greninja had a hard time battling her Gardevoir at first, as Gardevoir easily dodged its moves without even needing verbal orders from Diantha. Greninja then used Double Team to avoid an incoming Shadow Ball, but Gardevoir quickly fired off several Shadow Balls to destroy all copies and hit Greninja. After its Water Shuriken was dodged again, it managed to dodge Gardevoir's Moonblast, but was blown back into a tree by the blast caused by Moonblast's impact. Greninja then fired off two Water Shurikens, which again were easily dodged. It, however, managed to distract Gardevoir by launching a third one, allowing it to emerge from the smoke and hit the Embrace Pokémon with Cut. Greninja and Ash then reached the point where they could transform into Ash-Greninja. Diantha was greatly impressed by its special form, as Greninja started to gain the upper hand, being able to push Gardevoir back by overpowering its Shadow Ball with Cut. After a collision between Water Shuriken and Shadow Ball, Gardevoir proceeded to dodge Greninja's attacks again. This time, however, Greninja was able to keep up with Gardevoir's speedy movements and struck it with another Cut. As Greninja headed in using Aerial Ace, Diantha finally had Gardevoir Mega Evolve and repel Greninja's attack. Launched into the air, Greninja fired a Water Shuriken, which Gardevoir countered with Shadow Ball, the attacks colliding with equal force. Another Aerial Ace was then blocked by Gardevoir's Reflect, but Greninja immediately after used Double Team and Cut to push Gardevoir back, even through its Reflect. After destroying a Shadow Ball with Aerial Ace, Ash and Greninja reached Ash-Greninja's Final form, and the water veil that surrounded Greninja turned into a massive, back-mounted shuriken, much to everyone's shock. Greninja then attacked with its new shuriken while Gardevoir fired another Shadow Ball. This time, however, Greninja's Water Shuriken proved stronger and knocked Gardevoir off her feet. However, before the battle could progress any further, both Greninja and Ash passed out again from exhaustion. As a result, Gardevoir had to fend off Team Rocket while the two regained consciousness. Greninja and Ash soon recovered, and vowed to fully master their newfound transformation.

At the beginning of A Full-Strength Battle Surprise!, Greninja was shown battling an opponent Trainer's Scizor, using Double Team to dodge an incoming attack. Despite Scizor's attempts to hit Greninja with Bullet Punch, Greninja knocked the Pincer Pokémon out with Aerial Ace. Later, during the three-on-three battle between Ash and Sawyer, Greninja was Ash's final Pokémon, going up against Sawyer's Clawitzer. It easily dodged Clawitzer's attempts to hit it with Dragon Pulse and powered through Clawitzer's Ice Beam with Cut, finishing off Clawitzer with a single hit from said attack. It then battled its rival, Sceptile. At first they exchanged blows evenly, with Greninja using Aerial Ace to counter Leaf Blade. When Sceptile attempted to use Bullet Seed to hit Greninja, Greninja blocked this with Water Shuriken. It then used Double Team to dodge Sceptile's Leaf Blade, but was forced to jump back when Sceptile attacked with another Leaf Blade after destroying its copies within seconds. Greninja then attempted to hit Sceptile with Cut, but Sceptile dodged the attack and hit it with Leaf Storm. After getting up, Greninja attempted to blindside Sceptile with its speed and hit it with Aerial Ace, but Sceptile dodged at the last moment and knocked Greninja away with its tail. Ash then attempted to use the Ash-Greninja form as Greninja circled around Sceptile again, moving too fast to be seen. However, much to Ash's shock and surprise, Greninja was not able to transform. Taking advantage of a now distracted and shocked Ash, Sawyer had Sceptile hit Greninja with another Leaf Storm, followed by a Leaf Blade, knocking Greninja out and leaving everyone present shocked. Ash then thanked Greninja and recalled it, but he was apparently left doubtful of his ability to master the form.

In All Hail the Ice Battlefield!, Greninja was Ash's final Pokémon used in his Gym battle against Wulfric and faced his Avalugg. Although damaged by the Hail, which also gave Avalugg recovery because of its Ice Body ability, Greninja used its great speed to hit Avalugg with a strong Cut, after dodging the incoming Stone Edge. It then attacked with Aerial Ace, which Avalugg countered with Gyro Ball, repelling Greninja. Greninja then fired several Water Shurikens at Avalugg's feet while the latter kept spinning to shield itself. The cold, however, froze Avalugg's wet feet to the ground, leaving it wide open for another Cut. Now having gained the upper hand, Ash and Greninja were able to activate the Ash-Greninja form and completely overwhelmed Avalugg, sending it sliding backwards with a series of powerful hits from Aerial Ace. Wulfric, however, used Greninja's now even greater speed to his advantage by commanding Avalugg to use Avalanche, which was powered up due to Avalugg acting after its opponent, causing Ash visible pain. Greninja was then able to hit Avalugg with Cut after tearing through its Stone Edge, but Avalugg immediately retaliated by knocking Greninja in the air with another Stone Edge. After another exchange of blows with Aerial Ace and Avalanche, Greninja attacked with another Cut, but this time Avalugg caught it with Ice Fang, slowly freezing Greninja. Unable to escape Avalugg's fangs, Greninja was left vulnerable to a Gyro Ball, sending it flying into the Gym's wall, knocking it out, causing Ash to fall down as well. Ash later on oversaw Greninja lying unconscious in the Pokémon Center, blaming himself for their loss. Ash decides to leave Greninja and walked off into the Winding Woods alone.

It was later revealed that Greninja was awake while Ash talked to it in the Pokémon Center and the following morning, Serena, Clemont and Bonnie found out it had left on its own as well. While sitting in a tree somewhere in the Winding Woods, Greninja thought back to its losses against Sawyer's Sceptile and Wulfric's Avalugg, leaving it upset. Greninja was also pretty angry at Ash for leaving it, but after thinking back to Ash's words in the Pokémon Center, Greninja got angry at itself for not thinking about it sooner and decided to go and find him. Later, in the midst of a blizzard, Greninja came across Squishy in its 10% Form, who was looking for Ash as well. Using Zygarde Cells, Squishy managed to locate Ash, who was trying to help a bunch of Spewpa to get out of a tree branch above a cliff, and informed Greninja. When Ash reached for the last Spewpa, the branch broke and both fell down the ravine. Greninja, however, arrived just in time to save Ash from falling by grabbing him with its tongue. A sudden gust of wind, however, caused Ash to lose grip of the Spewpa. Determined to save Spewpa, Ash and Greninja were able to activate the Ash-Greninja form and with their feelings in sync, Greninja was able to reach the final stage and perfect the Ash-Greninja form. While Greninja jumped down the cliff, Ash, able to share Greninja's vision, gave Greninja the proper commands to get both it and Spewpa safely on the ground. Afterwards, Ash and Greninja along with some forest Pokémon sought shelter in a cave, where the two made up and promised to start over from zero again. Later on, Ash and Greninja reunited with the group again and after Pikachu defeated Team Rocket they returned to the Pokémon Center. At the Pokémon Center, Greninja showed Ash its Poké Ball and rolled it over to him, like the time when it was first caught, signifiying their resolve to start over again.

In the following episode, Greninja was Ash's final Pokémon during the rematch against Wulfric. It battled his Abomasnow this time, and despite a severe type-disadvantage and continuous damage from the Hail, it overpowered Abomasnow with its speedy attacks, hitting him hard with a super-effective Aerial Ace followed by Water Shuriken. Abomasnow tried countering with Energy Ball, but Greninja destroyed the attack with Cut, before it could be executed. It was obstructed by the Hail, however, giving Abomasnow a chance to properly charge his attacks and get a partly blocked hit in with Wood Hammer, freezing Greninja. Greninja, however, managed to break free from the ice and then transformed into Ash-Greninja. With its increased strength and speed, Greninja was now able to completely overpower Abomasnow, dealing major damage with Aerial Ace. Abomasnow tried hitting it with Wood Hammer, but Greninja easily outmaneuvered him and struck back with Cut before sending him flying into the ceiling using the big Water Shuriken on its back. Seeing the power of his opponent, Wulfric revealed his Key Stone to Ash and Mega Evolved Abomasnow. Against Mega Abomasnow, Greninja had a much harder time. Its Water Shuriken was immediately blocked by Ice Punch and Greninja then got hit by Ice Shard. Greninja, however, quickly retaliated by attacking with a Double Team-Cut combination, but Abomasnow was able to destroy all copies and hit the real Greninja with Wood Hammer. As Abomasnow fired another Ice Shard, Greninja headed in using Cut to destroy the shards and attack Abomasnow. Abomasnow, however, countered the attack with Ice Punch, knocking Greninja back as well as freezing its "knives". Greninja then, however, used the frozen knives as ice skates to dodge the incoming Wood Hammer and Ice Shard. It then forced Abomasnow to counter another Water Shuriken with Ice Punch, giving it the chance to finish Abomasnow off with a powerful Aerial Ace, giving Ash the win and earning him his final Kalos Badge, the Iceberg Badge.

In A League of His Own!, Ash used Greninja in the first round of the Lumiose Conference, where it faced Titus's Altaria. Right away, it got hit by Altaria's Dragon Pulse, who then proceeded to fire off a Draco Meteor. Greninja then transformed into Ash-Greninja, which shocked most of the people present, and was able to easily dodge the falling meteors and defeat Altaria with a single Water Shuriken.

In A Riveting Rivalry!, Greninja was used as Ash's final Pokémon in the semi-finals of the Lumiose Conference against Sawyer. It faced off in one final showdown against its rival Sceptile. After its Water Shuriken was destroyed by Sceptile's Dragon Claw, Greninja went for Double Team. Its clones were then wiped out by Frenzy Plant, but Greninja emerged unscathed and used Cut to clash with Sceptile's Leaf Blade. Both Pokémon then transformed to their respective more powerful forms, Ash-Greninja and Mega Sceptile. Greninja was able to cut through Sceptile's Frenzy Plant using Cut, before its Water Shuriken was countered by Dragon Claw again. Both Pokémon then kept exchanging and clashing with their powerful and fierce attacks, with Sceptile getting struck by powerful hits from Aerial Ace, before retaliating with Leaf Storm. After clashing using Cut and Leaf Blade again, Greninja was thrown into the air by Leaf Storm. As Sceptile was about to finish it off with Frenzy Plant, Greninja was able to regain its footing and run on top of the roots. Sceptile tried to corner Greninja with Frenzy Plant, but while using its shared senses with Ash and its full trust in him, Greninja was able to dodge every single Frenzy Plant and slice through them using Cut. As its back-mounted shuriken grew to massive size, Greninja fired off the Water Shuriken while Sceptile countered with Leaf Storm, causing a large explosion. After the smoke cleared, only Greninja remained standing, giving Ash the win and allowing him to advance to the finals of the Lumiose Conference.

In Down to the Fiery Finish!, Greninja was Ash's final Pokemon used in the finals against Alain, where it was sent out against Alain's Bisharp. Due to the rain, set up earlier by Goodra's Rain Dance, its Water-type attacks were powered up which allowed it to defeat Bisharp with Water Shuriken after dodging its Iron Head with Double Team. Alain then sent out his final Pokémon, Charizard, again. First, Charizard fired off a Flamethrower while both Pokémon headed towards each other. Greninja, however, avoided the attack and struck Charizard with a powerful Cut. After the rain cleared, it transformed into Ash-Greninja while Charizard Mega Evolved into Mega Charizard X. Greninja then started attacking by charging at Charizard while using Double Team. Charizard, however, wiped out its clones with Flamethrower, creating a huge cloud of smoke. Greninja then appeared from the smoke and fired off a Water Shuriken which was countered by Charizard's Dragon Claw. Both Pokémon then engaged in a brawl using Aerial Ace and Dragon Claw, but eventually Charizard managed to outmaneuver Greninja and knock it off its feet with Dragon Claw. After blocking a Flamethrower with Cut, Greninja slammed its Water Shuriken on the ground to counter Charizard's Blast Burn. As another cloud of smoke covered the field, Greninja was able to hit Charizard with Aerial Ace, slamming it onto the ground. Charizard, however, stood up and knocked it back with Dragon Claw. After clashing with Dragon Claw and Cut, Charizard attacked with Thunder Punch, but Greninja used Water Shuriken as a melee weapon to counter the attack and was able to strike Charizard with it. Ash and Alain then had their Pokémon use Water Shuriken and Blast Burn, respectively. As Greninja unleashed all of its power into the attack, its Shuriken grew to massive size and changed to a fiery red-orange color. Both Pokémon then fired off their powerful attacks with both scoring a direct hit on their opponent, causing another explosion and leaving the battlefield covered in smoke. Although initially both Pokémon were still standing, Greninja wasn't able to take the damage and fainted, causing Ash to end up as the Runner-Up of the Lumiose Conference.

Greninja was then taken captive by Lysandre with Ash and his other Pokémon in A Towering Takeover!. In the next episode, it and Ash were hit by Team Flare's Mega Evolution energy ray to control them, but they broke free using Bond Phenomenon. After Alain's Charizard broke Ash's other Pokémon free, Greninja, along with everyone else, battled against Lysandre's Pyroar and his Shiny Mega Gyarados. During the battle it struggled blocking Pyroar's Hyper Beam using Cut, but was aided by Noivern's Boomburst. Later on, after Pyroar, Noivern, Hawlucha, and Goodra had already been defeated, Greninja and Talonflame tried attacking Gyarados with Cut and Flame Charge, but were knocked in the air by Stone Edge. Despite being caught by Charizard, Gyarados slammed the three Pokémon to the ground with Dragon Tail, knocking Talonflame out. After Malva had appeared and decided to fight alongside Ash and Alain, Greninja blocked an incoming Incinerate with Water Shuriken. In the end, Greninja, Pikachu and Charizard were the only ones left facing Lysandre's Gyarados, although now aided by Malva's Mega Houndoom. The battle finally concluded in XY135, where Greninja and Charizard hit Gyarados with a respective Cut and Dragon Claw, allowing Pikachu to finish the Atrocious Pokémon off with a Thunderbolt.

Greninja later helped Serena's Braixen, Steven's Metagross, and Professor Sycamore's Garchomp fight against the Megalith Zygarde. Greninja managed to sense Chespie's location inside the creature and managed to throw a Water Shuriken into its body, marking the location. It, along with the other Pokémon, was eventually subdued by the creature's roots, but was freed by a combined attack from the Pokémon of all the Kalos Gym Leaders and Diantha. After strategizing, everyone combined their powers to fend off the Megalith Zygarde's roots, allowing Ash and Alain to reach its center and save Chespie, bringing the creature down. After the resurrection of the Megalith Zygarde, who was now controlled by Lysandre, Greninja, Pikachu, and Alain's Charizard managed to destroy Lysandre's control device, allowing Squishy and Z2 to destroy the Megalith Zygarde.

In XY139, Greninja detected the presence of one of the remnants of the Megalith Zygarde. After transforming into Ash-Greninja, it was able to see the source of the root under the ground and used Water Shuriken on it, causing the root to wither away. After Xerosic revealed that he was planning on creating Neo-Team Flare and kidnapped Clemont, Ash sent Greninja to follow after him. Greninja helped Ash and his friends defeat Xerosic in battle, leading to Xerosic's arrest. However, parts of the Megalith Zygarde still remained. After Squishy appeared and saved Bonnie from one of the roots, it led Greninja and the group to Z2, where Z2 requested for Greninja to help it and Squishy detect and destroy all of the remnants of the Megalith Zygarde. Greninja accepted Z2's request and bid farewell to Ash and his friends. In the following episode, Greninja was seen destroying a root, with Squishy and Z2 watching close by.

Personality and characteristics
As a Froakie, it was a stubborn, picky Pokémon, displayed by the fact that it had several other Trainers that it refused to listen to, either forcing them to return it to Professor Sycamore or abandoning them and returning to the lab itself. It is also extremely similar to Ash personality wise, as it is not afraid to leap into danger regardless of its own safety and doesn't back down from a fight. It is clear that it recognizes these traits in Ash, hence why it was finally willing to accept being taken into Ash's wing. It also has a sense of honor, as demonstrated when it attacked Fletchling just because it made Bonnie cry. In The Bamboozling Forest!, it is shown to have a good judgement of character, as it became suspicious of Meowth when he pretended to side with it, Pikachu, and Chespin under a temporary truce. Froakie is prone to blushing when praised, as shown when being thanked by Bonnie in A Battle of Aerial Mobility! and Fennekin in The Bamboozling Forest!. As shown in Kindergarten Chaos!, Greninja as a Froakie gets embarrassed when losing in a bad way, such as when it lost because of Attract.

Since evolving into a Frogadier, its personality remains largely the same. It is still shown to be loyal to Ash, as shown when it hugged him after its victory in the Coumarine City Gym battle. Greninja is a responsible Pokémon that can take initiative to protect friends and allies. In So You're Having a Bad Day!, it volunteered to scout ahead to protect Serena and Chespin after they had gotten separated from the group. Greninja also appears to be good with younger Pokémon and children. As a Froakie, in addition to challenging Fletchling for making Bonnie cry, it was able to befriend the timid Randall during one of Team Rocket's schemes. As a Frogadier, it can be seen looking after Dedenne in Under the Pledging Tree! while Ash and his friends were preparing gifts for their Pokémon. Greninja also seems to care deeply for its friends, as seen when it acted as bodyguard for Serena and Chespin in So You're Having a Bad Day!, and protected the two from a wild Pangoro.

Greninja seems to appreciate and respect bravery and selflessness, and as such, aims to be so itself. This is first shown when it took a hit for Pikachu during Team Rocket's attack despite not knowing Pikachu or his Trainer, and then proceeded to help them both in combat. It respects those with these traits, as it does Ash. Greninja was impressed and surprised by Ash's willingness to put himself in danger to help a Garchomp that wasn't his Pokémon and barely knew, and admired this show of self sacrifice and selflessness to the point Greninja as a Froakie went alongside Ash to face Garchomp. It also showed genuine concern for Ash's safety when Ash jumped off the Prism Tower. A lack of these traits in its previous Trainers may be what caused Greninja to leave them.

Greninja has been shown to enjoy battling, and seems to enjoy the opportunity to fight a strong opponent. Once recognizing Sawyer's Grovyle's strength, it developed a rivalry with it. It also seems to relish at both the thought, and the action of defeating a strong opponent, as seen when it grinned before fighting Sawyer's Grovyle, and defeating Grant's Onix.

Greninja's close bond with Ash was also one of his greatest insecurities, as their repeated failure to master the Ash-Greninja form started to weigh heavily on trainer and Pokémon alike. When Ash left Greninja in the Pokémon center after the loss to Wulfric, out of a sense of guilt for Greninja's injuries, a saddened Greninja gave chase as soon as he recovered. It was revealed Greninja also felt responsible for their loss. After fully synchronizing their feelings to save a Spewpa, however, Ash explained to Greninja why he wanted to become a Pokémon Trainer, and that he saw his Pokémon as his closest friends. After that, Greninja and Ash came to fully understand each other.

Ash-Greninja
Shortly after evolving into Greninja, through its strong bond with Ash, he can call upon a transformation similar to Mega Evolution, where it takes on an appearance resembling its Trainer while being covered in a water veil. In its final form, the water veil moves from around its body to its back and forms an "X" shape, which resemble wings, then the wings form into a small sphere shape of water on the middle of its back with a light blue ring in the middle of it and it then grows in size until it forms into a giant shuriken made of water. Its full capabilities were unknown, but it appears to give a significant boost in speed and power. In its completed form, it can rival the power of Mega Evolved Pokémon. This form comes with a side effect where whenever Greninja takes damage, the pain is shared with Ash in the same location where Greninja was hurt. Ash is also shown to be able to see from Greninja's point of view and will occasionally mimic Greninja's movements. Ash describes it as feeling like he "became" Greninja. It is revealed by Clemont's device that Ash and Greninja share the exact same heartbeat while Greninja is in the form and that the form can be accessed when Ash and Greninja's feelings synchronize. If the form is pushed too hard, it's possible for Ash to pass out from the resulting exhaustion and pain. The term Ash-Greninja (Japanese: サトシゲッコウガ Satoshi-Gekkouga) was officially coined by Bonnie in All Hail the Ice Battlefield!. During the next episode, Ash and Greninja made amends and were able to trigger the transformation at will. By the time of their rematch against Wulfric, Ash and Greninja were able to use the form without passing out, and although they still shared each others pain, it seemed to be more manageable for Ash to handle. During the Lumiose Conference, it is soon revealed by Professor Sycamore that the transformation Greninja had been going through is known as Bond Phenomenon.