In modern-day Okinawa, Saya Otonashi is an athletic teen leading a happy home life with her adoptive family. However, she struggles daily against memory loss that prevents her from remembering anything before one year ago. After Saya meets Hagi, a mysterious cellist, the pieces of the puzzle begin to unfold when he bestows a Japanese sword upon her. Saya doesn't understand the role Hagi plays in her destiny, until a blood-sucking chiropteran attacks her adoptive brother Kai and Saya is forced to fight for his life. With the help of Hagi, Saya rediscovers her past and embraces her role in battling the onslaught of chiropteran vampires that has plagued Japan for centuries. Set to music produced by Hans Zimmer, Blood+ is based on Blood the Last Vampire, the sixth-best selling anime of all time in the United States.