Saya Otonashi (音無小夜, Otonashi Saya) is the main protagonist of the series Blood+ and the firstborn of the daughters of the Chiropteran Mummy. She is a pure-blooded Chiropteran queen and Diva’s older twin sister as well as Hagi’s lover.
During her years at the Zoo, Saya was spoiled by the original Joel and therefore became very immature, self-centered, and rude. She herself realized this as a result of her friendships with Diva and Hagi, which help reveal and nurture her compassion for others. Overall, however, Saya was a bright, cheerful, and innocent person. After she unwittingly released the vengeful, bloodthirsty Diva upon her foster family and friends and accidentally turned Hagi into her chevalier, coupled with learning the truth about her life and her own inhuman nature, Saya lost her happy demeanor and becomes much more serious and plagued with doubts and guilt.
As a result of losing her memories and spending a year in Okinawa as an ordinary girl, with family and friends, Saya develops a sweet and caring albeit somewhat reserved personality. Kai later refers to her as being “a crybaby and a glutton”. The latter name suits her as she is much inclined to eat. According to Kaori, no matter how much she eats, she never gets fat. The constant hunger is possibly due to insufficient consumption of blood. At this time, she is troubled by her amnesia but only becomes increasingly insecure and worried as she learns more about her true identity and experiences more loss because of the Chiropterans.
Our hearts beat in the same rhythm, so why does time flow differently for the two of us?”