Kojima is a student at Sakura Middle School.
Kojima is a confident looking boy with short blonde hair. He is seen wearing the standard school uniform, consisting of a white dress shirt, black baggy pants, and black shoes.
Kojima seems more of the show-off type, even in a situation that could end badly for him.
Kojima's fighting skills have never been shown, but given his confidence, he has likely fought many times before. The odds of his fight against Takuya Yamamoto are 4-6 in his favour, which might suggest that he has already proven himself enough for punters to trust him.
(Source: Tokyo Revengers Wiki)