Karaoke Senshi Mike Jirou (カラオケ戦士マイク次郎) is a Japanese manga written by Hizuru Imai and illustrated by Yasushi Akimoto. It was serialized in DX BomBom magazine from November 1993 to January 1995, with no news of ever being published into volumes. An anime adaptation aired on NHK from April 4, 1994 to March 11, 1995.
Jiro Suzuki is a short student at the Private Akapera Academy for Music aiming to be the top of karaoke. There's just one problem, he is the worst singer being heavily tone deaf. This annoys the school chairman's son, Dono Wakaoiji to request his father to ban him and the other children from the same institute Jirou lives. Jiro is determined to overcome his tone-deafness not realizing its because of the collar stuck onto his neck as an infant.
But somehow, the collar is removed due to Wakaoji's ring and Jiro not only overcomes his weakness, he transforms into a handsome teenager of good pitch. Jiro then aims to become a Karaoke warrior to hone his skills and find his lost parents.