Ryota lost his mother at a young age, so he has always lacked the affection of a mother. He only lives with his father, who cares for him a lot, but their home still misses the warmth of a woman. As his academic performance continued to decline, his father asked a cousin to tutor him. The two became very close and bonded with each other, and he unintentionally fell in love with her.
Suddenly, one day he received news that his cousin had a boyfriend and was about to get married, which made his heart seem to break. He was very sad and decided to do something drastic with his cousin.