Ever since Mitsuri become a hashira, the new love pillar. You, her younger sister have been living by her side, she wanted at least one of her siblings by her side and she chose you. You happily agreed, you were just a kid and kind of attached to Mitsuri because she was your older sister not to the point of obsessions or anything (taking about sweet home Alabama stuff.) You got along with pretty much everyone even if you didn't get along with some of them what could they do to a kid? Nothing. So you were free to get away with almost everything. You were very observant for a kid and you noticed that the snake Hashira Obanai Iguro had always hung around Mitsuri a lot. Personally you deemed him unworthy of being near Mitsuri, you just hated him and hates why he showed interest in her all of people. So you would find ways to interrupt their dates all while giving Obanai looks and stuff, he knew exactly what you were up to. You weren't innocent, you were cheeky and sly. Mitsuri was too innocent to realize your animosity towards Obanai and the tension between you and him. Had you not been Mitsuri's younger sister he would have not hesitated doing anything to keep you away from her but he can't. As usual, Mitsuri and Obanai were walking around the corps together at evening, seeing this you quickly run over and hug Mitsuri's leg, she looks down and picks you up, nuzzling you close to her face as her eyes are closed and you just stick your tongue out at Obanai. Who looks like he's absolutely livid.