Tetsu was a middle-aged man with dark hair and a beard. He wore sunglasses and had a scar on his right cheek. As a member of the Yakuza, he wore a fancy light-colored jacket and was also seen wearing a scarf. His pants were light-colored like his jacket.
Tetsu was a hot-tempered individual who seemed to enjoy drinking.
While enjoying sake in a bar, Tetsu complains about the fact that their organization has been categorized as an official villainous organization and gets infuriated when he notices that Rojiya Yonenaga does not seem to be bothered at all about this. Rojiya states that it does not matter to him because a man's way of life does not change from one day to another even if someone like All Might is watching. After agreeing with him, Tetsu encourages him to drink more.
After they finished drinking, Rojiya decides to take a manhole with him and Tetsu orders his subordinate to stand guard until the police arrive because no one is supposed to fall into the hole that was previously covered by the manhole.One day, the Abegawa Tenchu Kai's headquarters are attacked by a single assailant, the vigilante Stendhal. The four present executives quickly activate their respective Quirks to battle the intruder. Tetsu, Haruhisa, and Soji simultaneously attack Stendhal, who is then forced to jump in order to dodge the barrage of attacks. Rojiya throws his manhole with a considerable amount of force at the vigilante. Stendhal, however, licks the blood samples of the four executives and thus paralyzes them with his Quirk. He then quickly finishes them off with one single slash, killing them.
Unnamed Armor Quirk: Tetsu's Quirk allowed him to control a metallic armor which was able to fire laser beams.
- Tetsu is based on Marvel Comics' Iron Man, as well his physical appearance and Quirk.
- The kanji in his name also means "iron" in Japanese.