Senjuro Rengoku

Rengoku Senjuro is the younger brother of Kyojuro Rengoku and the son of Shinjuro Rengoku and Ruka.

Demon Train arc
Senjuro first appears in Kyojuro's dream, asking if their father was happy to hear the news of Kyojuro's inauguration as the Flame Pillar. He is met with a different response and is saddened to hear the hopelessness of their father's mental situation.

Kyojuro later gives him words of encouragement and reassures him that things were not as bad as they seemed and to do his best throughout life.

Red Light District Arc
Senjuro appears once again after the battle with Lower Moon One Demon Enmu and Upper Moon Three Demon Akaza. He is seen sweeping the entrance outside of his home, wearing a saddened expression.