Yuuno Houzuki

A girl who Shinkur lived with when he was young and also his sparring partner. Her soft demeanor albeit with yandere tendencies triggered by other girls approaching Shinkur hides the fact that she is a strong fighter whom Shinkur acknowledges to be much stronger than himself despite her being older by just one year. Yno is upset that Shinkur has not realized he was her first love. Even now she still has feelings for Shinkur always finding excuses to spend time with him such as cooking meals for him. However her advances tend to be very threatening most likely because Shinkur always has another girl with him and scare him into just letting her hear what she wants. Yno resents the decision Shinkur made in deciding to move out her household to live on his own and fears he will change into a hooligan. She has made it very clear that she wants him back in the Hzuki household. Yno has a younger sister named Chizuru who is five who also has a crush on Shinkur. Even though the Hzuki family are no longer assassins their grandfather expects Yno and Chizuru to carry on the Hzuki family martial arts. In the anime Yno is much more assertive in her advances towards Shinkur and does not appear to have the yandere tendencies.