Onda Miku was just a regular high school girl who loves nails. But suddenly, she got into a terrible accident and the shinigami (death god) Sei fastened Thanato's Lover, his chain of death, onto her wrist! However, she was taken by mistake and was brought back to life but the chain cannot be removed until the end of her lifespan. She is now chained to Sei until then. Sei may be hot, but he is a bit scary. Being tied together with him, just what kind of fate awaits Miku!?