One of the main protagonists and a veteran superhero past his prime whose total disregard for private property when fighting against crime earned him the nickname "Crusher of Justice". Currently he is the least popular among the heroes of Sternbild City and his company has been taken over. Now he is forced by his new employers to become Barnaby's partner against his will. He has a daughter named Kaede who, like most people of the city, is unaware of his secret identity. He possesses the power to increase his physical abilities hundredfold for 5 minutes, and can only do so again after a one hour cooldown. His new suit includes advertisements for the Japanese S.H. Figuarts toy line and Japanese media company SoftBank. Having been inspired by a hero named Legend, who helped him to accept his powers, Kotetsu has traditional ideals of justice, always relying on his instincts and putting lives over ratings.
Kotetsu usually wears a white vest over a green shirt with a black-and-white-spots tie along with dark green or black pants and a grey and white hat. He wears his Hero Bracelet on his right arm at all times. He has light brown hair and a brown beard. He also has gold colored eyes.