Freshman Kurogane Taito was always an ordinary, regular guy, except for a promise made to the beautiful vampire, Saitohimea nine years ago.

Taito has been really sleepy lately, and keeps dreaming of a female vampire who says she has given him her "poison." Sometimes he even thinks he hears her voice when he's awake. But after surviving an accident that should have killed him, Taito's world changes drastically and he realizes that his dreams are more real than he thought.

When Taito Kurogane was little he met Himea Saito, a vampire girl who gave him a curse of living after dying, but dies after being killed the 7th time. Himea was then taken away from Taito, who loses all memory of her. After 9 years, Taito is now in high school, and has freed Himea, and they begin to catch up on the 9 years away from each other.—Anime News Network

The first-year high school student Kurogane Taito is a disillusioned youth, and no longer believes 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: nine years ago, the young Taito met Saito Himea, an elder vampire, and made a pact with her. Now, as Taito's memories slowly return, after an accident he should not have been able to survive, he will remember the girl who had been kidnapped and kept imprisoned for the past nine years, waiting for him to free her.—AniDB