Tenshi no Tameiki(1982)

Chuo Kobayakawa, a senior in high school, is the captain of the rugby team. He has a strong sense of justice, but he has a violent temper and stands out at school, where he is considered a problem child by the teachers. Chuo fell in love with Shiori Origuchi, a second-year member of the tennis club and a student council member. Chuo tries to ask her out, but she flatly rejects Chuo, saying that she can't go out with him. However, Chuo refuses to give up, and Shiori gradually begins to open up to Chuo. But Shiori has a big secret in her heart that she can never tell him...! This is a dramatic love story full of youthful suspense.

(Source: Shueisha, translated)