合コンで出会った超絶美少女が昔助けた人でとんでもない地雷系女（姉はとんでもないヤンデレ）だった。 (Associated Names)

Tsukasa Kirishima is a freshman in college. He lost his parents in high school, and in his second year of high school, he once saved a very beautiful girl from being attacked by a pervert near his house. He sometimes thinks about it, but when a male friend who goes to the same university invites…