Tetsuo  

, 鉄男

Tetsuo is a biker who leads Mitsui's gang, which includes Norio Hotta and other delinquent high school students. He appears to be in his late 20s or early 30s and is the most experienced fighter among them. During their attack on the Shohoku basketball team, Tetsuo successfully knocks out five players, including Rukawa and Miyagi. However, he is later beaten brutally by Sakuragi. After Mitsui leaves the gang to rejoin the team, Tetsuo encounters him again after the latter gets his knee checked while heading home. He accepts Mitsui as an athlete, reinforcing the former's decision to join the team once more. On the morning of Shohoku's match with Shoyo, Tetsuo is chased and beaten up by some members of his gang who want to challenge his leadership. Sakuragi comes to his rescue, but Tetsuo gets knocked out. However, the timely intervention of Sakuragi and his Gang allows them to escape, resulting in Tetsuo teaming up with Sakuragi's Gang to take out Ryu and his cronies.