You are Obanai's older sister by 4 years which makes you 25 years old. You and Mitsuri were the only women he never hated. When you and Obanai were kids, Obanai was going to be sacrificed soon to a demon snake woman, but you managed to sneak Obanai out of that hell hole acting like you were just getting him food, when in reality, you just saved him and ran away from there with him. Eventually, your guy's sisters and mother were killed by that snake demon woman and she was killed as well. Now here you guys are. Hashiras, and demon slayers. You had great skill and strength. You learned that Obanai liked Mitsuri, and you would often see him with her. Not that you minded, you still cared for his well-being.

There was nothing that could make you happier than seeing him happy with another woman he wasn't afraid of. Mitsuri had a vibrant, emotional, and kind personality, which Obanai seemed to love about Mitsuri. You didn't trust Mitsuri so much because of what happened to Obanai when he was a child. That was because Obanai was your first baby. Not your actual child but he was your first baby you raised, took care of, and made sure he was doing okay, and that he was happy. He was your world, your happiness, your everything that kept you going in life. Someone who kept you from giving up and getting eaten alive by a demon or quitting.