Kousei Arima is a child prodigy known as the Human Metronome for playing the piano with precision and perfection. Guided by a strict mother and rigorous training, Kousei dominates every competition he enters, earning the admiration of his musical peers and praise from audiences. When his mother suddenly passes away, the subsequent trauma makes him unable to hear the sound of a piano, and he never takes the stage thereafter. Nowadays, Kousei lives a quiet and unassuming life as a junior high school student alongside his friends Tsubaki Sawabe and Ryouta Watari. While struggling to get over his mother's death, he continues to cling to music. His monochrome life turns upside down the day he encounters the eccentric violinist Kaori Miyazono, who thrusts him back into the spotlight as her accompanist. Through a little lie, these two young musicians grow closer together as Kaori tries to fill Kousei's world with color.

On the last Valentine's Day before her high school entrance exams, Nana Suzuki tries to build up the courage to confess to her longtime crush. However, when her chocolates are accidentally ruined, she rushes back to her house to make more—not realizing that the microwave has been turned into a strange invention by her grandfather. Suddenly, six additional copies of Nana appear, each possessing their own extreme personality and a crystal that grants them magic powers! With her plans ruined, Nana vows to confess to her crush in her first year of high school. The only problem is that her crush is top student Yuuichi Kamichika, and following him to his elite high school will mean that she has to hit the books. With six new allies to help her, Nana begins to prepare for anything that the exam season might throw at her.

OVAs of History's Strongest Disciple Kenichi bundled with volumes 46, 47, 49, 53, 54, 55, & 56 of the manga.

A brief summary of Kenichi's new life at Ryouzanpaku. Included as a bonus on the DVD volumes of the Shijou Saikyou no Deshi Kenichi OVA.