Akira Midousuji

Midousuji has a sadistic and eccentric personality; he'll do anything to win including constantly causing others emotional distress. He appears to particularly enjoy harassing Imaizumi, but anyone he races against becomes a target of his mind games. Midousuji has a tendency to call others, including his own team members "small fry." His most commonly used phrase seems to be the word "gross." Midousuji's desire to show off his teeth probably stems from the fact that his mother said his teeth were beautiful when he was a child.

(Source: Yowamushi Pedal Wiki)