Husband: Shinjuro Rengoku Eldest Son: Kyojuro Rengoku Second Son: Senjuro Rengoku A woman of remarkable beauty and an upright heart, Kyojuro deeply respects his mother and was greatly influenced by her. She seems to have had an excellent relationship with her husband as well as her sons. Kyojuro was very strong, taking after his father Shinjuro. However, whenever he showed his strength, Ruka would tell him: "Helping the weak is the duty of those born strong. It is a mission that you must take responsibility for and fulfill. You must never forget this." She is so gentle that she uses polite speech even when addressing her children. While she possesses great beauty, she is also a person of exceptional character who rarely shows changes in her expression. However, that is only on the surface; she is the owner of a warm heart, so much so that her family truly cherishes her. She usually dresses neatly in a blue floral-patterned kimono. However, she is in poor health, her complexion has faded, and her skin has turned pale; she is in a critical condition where she could pass away at any moment. Shinjuro works hard as the Flame Hashira of the Demon Slayer Corps and teaches swordsmanship to the children.