Seijūrō Shin (進 清十郎, Shin Seijūrō) is the Linebacker for Ojo White Knights, and the ace of the team. he is known for his strength, speed, and his famous Spear Tackle and was considered the strongest Linebacker in Japan. later on in the series, he also plays offense as a fullback. 

He is the most prominent rival of the series' main character, Sena Kobayakawa the Running Back of the Deimon Devil Bat.

Shin is considered the strongest and fastest linebacker in the history of Japan. His signature move is the Spear Tackle, a powerful one-arm thrust that can stop any opponent, and later, agonizing players so much that they refuse to touch the ball ever again.