Senjuro is Kyojuro Rengoku, the flame hashiras younger brother. He is very shy and timid, and he is abused by his alcoholic father, Shinjuro. He has the signature flamed themed hair and eyes, but he wears a white  yukata and juban with darker umanori-styled hakama pants. He tried to become a demonslayer like his brother but was too weak, so he often is seen doing chores. Kyojuro's death absolutely crushed him.