Itsuka Tenma no Kuro Usagi Koukouhen: Kurenai Gekkou no Seitokaishitsu

Taito has been really sleepy lately, and keeps dreaming of a particular vampire who says she has given him her "poison". Sometimes he even thinks he hallucinates 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.