Reigning in the prestigious school of young ladies is Jill Laine Mariebell, the cool-headed and perfect student council president. Known as the Ice Queen for her righteousness and dictatorship, she was feared not only by her students, but by her teachers as well.

One night, Jill is stabbed in her courtyard and her life is in danger. A young shinigami, Noah, appeared there. He says he will return Jill to the past if he gives her half her lifespan. Jill, who felt a strong resentment towards the criminal who tried to kill her, agrees and returns to the past to find the criminal with Noah. But for a short while, Jill is about to be killed by someone again.... What is the purpose of the criminal who keeps trying to kill her, and can Jill find the criminal?