Over Drive(2005)

Shinozaki Mikoto is a timid and short-statured 15-year-old highschool sophomore who often gets picked on at school. The girl whom he admires, Fukazawa Yuki, happens to discover an overwhelming strength of heart behind his shy appearance. In efforts to promote the school's emergent cycling club, she introduces cycling to Mikoto and tries to talk him into joining the club, as she's thoroughly convinced he has a special inner drive that makes him a promising cyclist. How far will cycling take Mikoto, not only materialistically, but in his growth as a person?

(Source: Japanese publisher, translated)