Kanjin hardly view their servants as human. Even less so when they are different. Asagi is different. Both a man and a woman.

In the wake of his failure to protect a boy he saw as a son from their abusive master, Asagi is sold into the house of a young nobleman, Mahiro, who is the opposite of everything Asagi has ever known--gentle, kind, and generous.

Mahiro bonds with Asagi and their friendship blooms into a deep and profound love. But when Asagi is poisoned out of jealousy, Mahiro reveals himself to be youkai, a demon who feeds on blood, and he has no choice but to turn Asagi to save his life.
Asagi awakes reborn, strong, and eternally youthful. But the price for Asagi's new life is high.

The blood of the innocent.

Just as Asagi's trust in Mahiro falters, the boy he failed to protect, now a man, reappears.

New master, same threat.

With both a literal and proverbial monster at the door, Asagi must decide what it means to be human to protect what he loves most.