Kirihito Kamachi/Synopsis

History
Kirihito was a person who liked to consume Trigger. Although the Hotta brothers warned him to keep away from the more suspicious drugs and tried to dissuade him to buy the new adulterated version, he ignored them. The Villain Factory, responsible for distributing the adulterated Trigger, saw potential in his Quirk, and decided to kidnap Kirihito and experiment on him.

Osaka Incident Arc
Time later the Factory release him in the streets of Naruhata. Kirihito, already transformed into Next-Level Villain, is rampaging when The Crawler confronts him. However, the vigilante is overwhelmed by Kirihito's strength and speed, and the villain chases the boy down the street. Captain Celebrity arrives and easily defeats the villain.

Sky Egg Bombing Arc
After spending some time in prison, he is released and all his charges were dropped after the police learned that he was a victim, since the Factory bio-engineered on him. However, when he returns to his apartment, he discovers that he can’t get in the place because his new body is too big. Therefore, the Hotta Brothers decide to welcome him and let him live in his warehouse. Naomasa Tsukauchi and Shota Aizawa goes to the Hotta brothers' shop to meet with him and talk about his kidnapping by the Villain Factory, but the only thing that he wants to complain is about how today's society discriminates against those who are physically different, like him. The others consider that he just exaggerates too much.

Some time later, Kirihito gets involved in a fight against Octoid, another Next-Level Villain, which had been attracted to the warehouse where he lives by Shota, Koichi and the Hotta brothers. Kamachi faces Octoid, but since he no longer consumes Trigger, he is much weaker that before, being overtaken by Octoid. Fortunately the others intervene and manage to capture the Next-Level Villain. However, another entanglement with Kirihito release Octoid by accident, who escapes, only to being found afterwards badly wounded for unknown reasons.

School Days Arc
At some point Octoid, whose real name is Ikajiro Takobe, got discharged, and the Hotta brothers decide to take him in by letting him live with Kirihito in tents in the place where his warehouse used to be. Around that time, the Hotta brothers also considered stop dealing with Trigger and closing the Recycle Shop, and opening a cafe-shop. They plan to use the villain damage insurance payment for the destruction of their warehouse and the welfare subsidy that Takobe and Kirihito get for oversized housing for that.

A few days later, Shota and Koichi go to the Recycle Shop, and the brothers,Kirihito and Ikajiro explain the situation and their plans for the future.