Senjuro has a similar appearance to his brother, Kyojuro Rengoku, and father, Shinjuro Rengoku, possessing unruly golden hair that flares out around his face, becoming red near the ends above his ears and shoulders, that he wears messily tied back behind his head. He has fair skin and large, golden eyes that transitioned to a red hue with white pupils, that are slanted inwards and shaped so as to give him a determined yet kind appearance. He has a gentle, modest personality, shy, meek, sweet.