Kazuna is tormented by his strange new disease: a violent and irrepressible craving for blood. As his long-lost sister Chizuna reveals the secrets of his past, the two find themselves drawn together as their destinies intertwine. As the siblings grow increasingly alienated from the world and alone because of their blood-borne disease, relationships with others close to them fall by the wayside.

Kazuna Takashiro
A brooding teen. After his mother died when he was very young, his father inexplicably sent him to live with a family friend, 'Uncle' Shin Eda. Kazuna was recently reunited with his older sister, and she tells him some shocking news: He comes from a family of vampires!

Chizuna Takashiro
Kazuna's older sister. She wants to protect Kazuma from danger, fearful that he will not be able to constrain his vampiric urges. Chizuna is also cursed with the vampire's hunger for blood.

Yaegashi
Kazuna's friend. She's an amazing artist. Kazuna clearly has a crush on her, but he's afraid of putting her in danger.

'Uncle' Shin Eda
A family friend of Kazuna's and Chizuna's father. 'Uncle' Eda has raised Kazuna ever since his mother died.

'Aunt' Natsuko Eda
Shin's wife, and Kazuna's 'Aunt.' She wants to officially adopt Kazuna.

Minase
An old friend of Kazuma's and Chizuna's father. As a doctor, he aids Chizuna with her 'condition.'

Kei Toume
Kei Toume is on the cutting edge of Japan's horror revolution. His smash-hit Hitsuji no Uta spawned a live-action film and an OVA anime series. His previous series, Kurogane, was historical samurai story with a bizarre twist -- the samurai was a robot.