Nekomaru Nidai
Nidai is a vigorous, openhearted student who is passionate about supporting athletes but suffers from dyspepsia (AKA indigestion.) He shouts a lot but for his own reasons. He is close to Akane Owari and trains with her a lot.
As a coach, he trained a lot of good players including figure skaters that can perform 6 revolutions per spin and tennis players that were able to turn an almost-win into a win with a total of 36 hours of playing time.
As a kid, Nidai was born with a heart disease which made him very frail to the point of staying in the hospital. There, he met a kid named Daisuke, who also had the same problem. Nidai noticed that a lot of people visit Daisuke, and it was revealed that he is a manager of a sports team. Sadly, Daisuke didn’t manage to see his team’s victory and there, and Nidai became inspired to become a coach and continue his friend’s dream.
After defending Akane from Monokuma in Chapter 3, he is sent to hospital with seriously fatal injuries. In Chapter 4, he returns as a cyborg with his mind transferred in. He was then later killed in the same chapter.