Tenga Onigawara

Tenga Onigawara is a student at Salt Middle School, a school with a reputation for producing delinquents, and his short temper and tendency to get into fights fit that reputation well. Things get worse for him after Shigeo Kageyama, the psychic protagonist of Mob Psycho 100, accidentally causes serious damage at a rival school, Black Vinegar Middle School, during an unrelated incident. Onigawara ends up accidentally starting a wild rumor about it afterward, a story that spirals into something called the 'White T-Poison' scare, and the fallout from that rumor spreads further trouble his way.

A classmate named Shinji Kamuro frames Onigawara for something he did not do, turning most of his own class against him in the process. Rather than let that isolation push him further into trouble, Onigawara chooses to change: he decides to work on bettering himself and ends up joining the Body Improvement Club, a group built around physical training and self-discipline, as an unofficial member even though its official leader is a classmate named Musashi Goda.

That choice marks a real turning point for him. Where Onigawara's early appearances paint him as just another short-tempered troublemaker, his decision to join the club shows a willingness to take responsibility for his own reputation rather than simply blame everyone else for how he is seen.