Blood+ (stylized as BLOOD+ and pronounced "Blood Plus") is a Japanese anime television series produced by Production I.G and Aniplex and directed and written by Junichi Fujisaku.

Under the care of her adoptive family, the protagonist Saya Otonashi had been living the life of an anemic amnesiac, but otherwise ordinary schoolgirl.

However, her happy life is shattered when she is attacked by a Chiropteran, a hematophagous bat-like creature that lives by feeding on human blood.

Armed with her special katana, Saya embarks on a journey with her family, friends, allies, and her chevalier Haji, to rid the world of the Chiropteran threat and recover her identity.

The opening and ending themes are performed by a variety of artists, including Hitomi Takahashi, Chitose Hajime, Hyde, Mika Nakashima, Angela Aki, Uverworld, Jinn, and K.[19] In an interview with Production I.G staff, Omatsu noted that he felt Sony did an excellent job of providing music fitting for each season, as did the team of Zimmer and Mancina.

The soundtrack included a DVD with a special episode telling some of Hagi's backstory and a music video with Furukawa playing the first track, "Prelude" (プレリュード).

[21] Blood+ Complete Best, released October 25, 2006, is a limited edition compilation set containing a CD, a DVD, and an eighty-page booklet that includes a full episode guide and some final notes from the series production staff.

The CD includes the full versions of all eight series' opening and ending theme songs, as well as last two instrumental tracks from the first soundtrack.

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.

[25] The second adaptation titled Blood+ Russian Rose (BLOOD+ ロシアン・ローズ), is a two-volume series written by Karino Minazuki and illustrated by Ryō Takagi.

The series, published under Kadokawa's female oriented label Beans Bunko, details Saya and Hagi's lives at the start of the 20th century and the Russian Revolution.

[23] In 2017, Fujisaku wrote a third novelization of Blood+, titled Blood#, which takes place after the series finale, focusing on Diva's grown children, Hibiki and Kanade.

[25] The game is set during the first season of the series, and features an original story in which Saya, joined by three friends from school, investigates the mystery of her father's disappearance.

In September 2006, Newtype released Blood+ Encyclopedia, a special issue fan book that includes interviews with the staff and cast, an episode guide, and information on the related media – the manga, novels and video games.

The drop in viewership became more pronounced after NHK Educational TV's baseball anime Major premiered on a competing time slot.

[33] Carl Kimlinger of Anime News Network gave the series an overall score of B stating, "The plot is propulsive, never lingering for long in one place, yet never rushing to leave.

[34] In December 2005, Blood+ was one of several anime series selected as being a "recommended as an excellent work" at the 9th annual Japanese Media Arts Festival.