Детектив-убийца Цукимизуки Рикай

Two years after his father's death, a girl in a wheelchair suddenly appears and becomes Tsuzuki Ui's classmate. He soon learns that she is a detective from the wealthiest family in Japan, and that it is not the first time they have met each other. She came to investigate Ui's father's death — an alleged suicide — and for some reason, she strongly suspects Ui's little sister Haruka…