Ruka has defined facial features, such as her sharp nose and long eyebrows. She has large glazing eyes, and a small mouth, with semi-long black hair tied loosely at the end in a ponytail. She is only seen wearing a traditional kimono in a series of flashbacks.
As opposed to her husband Shinjuro's loud personality, Ruka is depicted as being wise, gentle and graceful. In the manga, she is seen as having a strong morale values, teaching Kyojuro the importance of his life and the need to use his strength in order to protect the weak and helpless people in the world as his primal duty.
Later, her husband speculated that their two sons have wonderful personalities mainly because of her biological influence.
Ruka is the mother of both Senjuro and Kyojuro, and is the wife of Shinjuro. Some time after giving birth to Senjuro, she developed a disease and was left bedridden up until her death.