Seijuro Shin 進清十郎

The ace linebacker of the Oujouu White Knights American football team and Sena Kobayakawa's main rival. Shin is a silent, seemingly unsociable person. Despite this, his friends include his teammates Haruto Sakuraba and Makoto Ootawara. After the Oujou's coach, Shoji Gunpei, noticed his talent when he first tried out for the Oujou American football team with Sakuraba, he told the seniors to make sure Shin never gets recruited by any other club than the American football club.