Hundreds of years ago the nine Oni generals were sealed in masks, where they were helpless and could not use their powers.
In The Demon Behind, Ikazuki's mask is found by a fisherman, but it was snatched by the Enforcers and then by the Chans. To find out how to defeat Tarakudo, Jade uses the Rat Talisman to make the mask come to life so they could interrogate him. The reanimated Ikazuki immediately attempted to summon his Shadowkhan, but he found he needed a host to do so. He showed interest in Tohru, but by nature, Tohru was repulsed by the thought of binding to an Oni. Some petty remarks between Tohru and Uncle spark an argument, and in the confusion, Ikazuki escapes Section 13. What with one thing and another, Ikazuki lands face-down in a car and Finn sits on him, resulting in Ikazuki (still thinking and speaking for himself) being bound to Finn's rear. Ikazuki summons the Samurai Khan to capture Tohru, intending to use the removal potion to have his mask moved onto Tohru's face. To his fury, Finn himself uses the potion to remove the mask and abandon it partly in rebellion against Ikazuki's arrogance, but mainly because he has to go to the bathroom. Jade then removes the Talisman from the mask.
In Ninja Twilight, after the nine masks was joined together, all of the Oni generals were freed and tried to destroy the world. Ikazuki stays in Section 13 and monitors the Oni's progress, removing the onion odor to allow Tarakudo in. However, Tarakudo gets the willies, sensing interference. He captures the J-Team and imprisons them in Section 13 cells. Then, the discovery of Tarakudo's mask causes a fight. He tries to join, only to be tackled by Viper and El Toro. After Jade put Tarakudo's mask on his face, all the Oni and Shadowkhan were imprisoned within.
- The Demon Behind
- Ninja Twilight
- "I shall devour your brains!" The Demon Behind
- "Your threats do not interest me, but he does. With my magnificent face atop your mighty form, we would be unstoppable." The Demon Behind
- "Remove your hands from my face!" The Demon Behind
- "Many thanks for our freedom Chan. Now it is time to surrender yours." Ninja Twilight
- "Summon the Dark Ones." Ninja Twilight
- "And our shadow armies are advancing as we speak, Master Tarakudo." Ninja Twilight
- (witnesses Tarakudo getting the willies mid sentence) "The forces of 'oohoohoohooh'?" Ninja Twilight
- "It would seem humankind's last line of defense..." (initiating a victory speech to the imprisoned J-Team, which Tarakudo finishes) Ninja Twilight
- He is the only Oni to talk apart from Tarakudo.
- Ikazuki is the only named Oni general.
- His name (雷, ikazuchi) means thunder.