Raised from a young age by Mr. Rurimiso of the Holy Tone-Deaf Family, Mike Jirou (voiced by Minami Takayama) studies karaoke singing at the private A Cappella School. Because he is tone-deaf, his singing can shatter windows and drive his classmates to despair. The arrogant Wakaoji-dono (voiced by Yuko Kobayashi), who believes herself to be the best singer, looks down on him and complains to her father, the school chairman Wakaoji-daidokoro (voiced by Masaharu Sato), demanding Jirou's expulsion from the school. Jirou's good friend, Funaki Yoshimichi (voiced by Tsutomu Kashiwakura), whose family runs the "Snake's Path" karaoke chain, is determined to sing well. Jirou pesters Funaki to take him to practice. Wakaoji-dono and his younger sister, Wakaoji Hime (voiced by Hiroko Emori), with ill intentions, invite Jirou to sing karaoke at a place that is actually a prank house. Just as Jirou is about to face danger, he receives a microphone left by his parents that can transform him into a true Karaoke Mic Warrior. Wakaoji-dono tries to steal the microphone but accidentally uses his own ring to unlock Jirou's sealed vocal cords. Unexpectedly, after the vocal cords are unlocked, Jirou's voice becomes heavenly...