Руко Аясэ

Юто's older sister, who lives with him, enjoys drinking. She also loves her younger brother, but expresses her affection through light teasing and forces him to cook for her, give her massages, and do various other things. In the first season, upon their first meeting, she realized that Yuta and Haruka already have feelings for each other and asked Haruka to take care of Yuta. Her weapon is a sword.