Rinji (麟児, Rinji) was a shinobi from Otogakure and a member of Team Guren. He also was an underling of Orochimaru.
Rinji had a laid back attitude and was rarely worked up about anything. At the same time, he was shown to have sharp intellect and was a planning type. He was also somewhat ambitious, as he wanted to report to Orochimaru in Kabuto's place, threatening his position as Orochimaru's right-hand man, which led to him being killed by Kabuto.
Rinji had dark brown hair with black eyes. His outfit consisted of a purple loose fitting vest that showed his chest. The rest of his mid-section was covered with bandages. He wore a light blue poncho-like item around his neck and also wore black wrist warmers and tan pants with dark brown sandals.
Rinji was a bat-user; he had the ability to manipulate bats via the method Bat Controlling, and use them to create ultrasonic waves so that he could communicate with bats, allowing him to survey the surroundings and give battle instructions to his subordinates. He also appeared to have a sonar-like power of his own that allows him to detect sound from a large radius. By using sound his bats produce as a weapon, he can affect the opponent's mind and equilibrium, and also grants him immunity from Guren's Crystal Release technique.
Bat Controlling: Rinji has the special ability to produce ultrasonic waves and understand them. This way he can talk with bats, who use ultrasonic waves for communication. He is able to give them orders, like to search the area around him, and they seem to consider him a friend. He can use these bats to release powerful sonic waves.
Bat Controlling: Ultrasonic Mind Waves: Once Rinji controls his bats, he commands them to produce high frequency ultrasonic waves that affect the mind of the opponent.
These bats (along with Shino's evolving insect strategy) have been the only effective counters to the Crystal Release. The ultrasound waves move at a frequency that allowed the crystal to breakdown at a molecular level, allowing dispersion of crystal particles back into the air.
After the selection battle Kabuto Yakushi and Guren held in the hideout, Rinji became Guren's subordinate. When Guren returned, she ordered him and the rest of his team to dispose of Kakashi and Team Kurenai. During which the fight, he took on the role of leader and presumably used his sonar powers to allow his team to fight in Kigiri's Destroying Smell Smoke Prison. After feeling that he analysed his opponent's skills enough, he was ready to finish them, until he detected Shino Aburame's insects coming. Feeling the increased danger, he ordered his men to retreat.
Later, Rinji and the rest of the team came to Guren's aid when her crystal barrier was destroyed by Naruto and Gamatatsu. After retreating, the team, minus Gozu, was ordered to stop Team Kakashi and Team Kurenai from pursuing them. Rinji used his bats to try and catch them by surprise, but Hinata Hyūga's Byakugan nullified his efforts. The battle was interrupted by the actions of the Three-Tails and Rinji and his team had no choice, but to fall back again.
After meeting up with Kabuto again, it was then revealed that Rinji was a spy for Orochimaru who was ordered to keep an eye on Guren. It was also revealed that he had spent years acting as spy, inserting himself into villages and even as a fellow prisoner in Orochimaru's dungeon. When talking to Gozu, he claimed his actions were to aid his sickly sister from a far off village. When they were once again sent to stop the Konoha shinobi, Rinji did not participate, allowing his team-mates to be defeated by Team Two. Instead, he noticed the attempted sealing of the Three-Tails. When he was unable to stop it by himself, he had Guren come help him and they ultimately proved successful.
Rinji continued to show a number of uncharacteristic behaviour after that, but this was later revealed to be Kabuto disguised as Rinji; Kabuto revealed that he killed the real Rinji. When Guren planned to run away with Yūkimaru, Kabuto summoned the real Rinji using his Dead Soul Technique, who fought with Guren. His bats' ultrasonic waves were shown to break Guren's Crystal Release, making the Crystal Release useless against Rinji. To protect Yukimaru, Guren crystallised herself, along with Rinji, which caused them to fall into the lake.
- Despite Rinji's troubled relation with Kabuto, they ironically shared one trait: they both had spent many years acting as spies and had a knack for appearing genuinely cheerful and kind-hearted to strangers to better deceive them.
- Rinji was shown fighting Sakura in the fourth opening, but this never occurred, as he was killed by Kabuto before anything happened.