1st year high school student Kurogane Taito is a disillusioned youth. He has thrown away the belief that hard work and effort will be compensated. Now, he simply exists as the days pass him by. However, there is something that he has forgotten. A stolen memory of a girl, a pact, and a curse. 9 years ago, the young Taito had met Saito Himea, the eldest vampire, and made a pact with her.