After surviving the death of his parents, protagonist Takami Akitoshi is left to live with his beautiful older sister, Hitomi, alone, hiding his lust for her. One day, a mysterious girl enters his room. Her name is Mina. She is Death. She explains to him that she has come to him to take his soul because he has reached the limit of his lifespan. Hearing him scream, Hitomi comes running to him. After she learns the situation, she asks, Mina to save him. Mini is touched by her determination, and shows them a way to extend his lifespan. If Akitoshi impregnates Hitomi, then according to shinigami law, the person who escapes the god of death extends his life by another 100 years.