Blood+

Under the care of her adoptive family, Saya Otonashi has been living the life of an anemic, amnesiac, but otherwise ordinary schoolgirl. Saya’s happy life is shattered when she is attacked by a chiropteran, learning that she is the only one who can defeat them.

Armed with her katana, Saya embarks on a journey with her family, allies, and her chevalier, Hagi, to rid the world of chiropteran and rediscover her identity. The course of the journey reveals the background history of the chiropterans and Saya's very deep past, which extends into the mid-18th century.
The series is initially set in present day (September 2005) Okinawa City (Koza), on Okinawa Island, near the US Kadena Air Base. In the course of the series, Saya visits locations across the world, fighting enemy chiropteran and searching for her origins.

To lead up to the Blood+ anime series, three Blood+ manga series were released and published in three different manga magazines. The tankobon volumes of all three series were published by Kadokawa Shoten. Blood+, by Asuka Katsura, is a five-volume series that first premiered in Monthly Shonen Ace in July 2005. It covers the same story events as the anime series. Blood+: Adagio was written by Kumiko Suekane. It is a two-volume series that premiered in the September 2005 issue of Beans Ace Magazine and follows Saya and Hagi's experiences during the Russian Revolution.


The third series, Blood+: Kowloon Nights, released in Japan as Blood+ Yakojoshi, is a single tankobon series by Hirotaka Kisaragi. It premiered in the September issue of Asuka Ciel. Set in Shanghai, it follows Hagi as he searches for Saya and the complications he must deal with. Unlike the other Blood+ manga adaptations, which are both shonen works, Blood+ Yako Joshi is a shojo manga, particularly of the shonen-ai (or Boy's Love) genre. All three manga adaptations have been licensed for release in English in North America by Dark Horse Comics.