Blood + Episode 1 - First Kiss

Saya Otonashi seems to be a fairly normal high school girl, except that she has no memory of her life beyond a year ago and she must have regular blood transfusions. Later, she comes across a man playing a cello whose song triggers a vague memory. When Saya goes to the school that night to retrieve her forgotten shoes, the cello player approaches her holding a dagger. Saya flees and runs into a teacher, who is then killed by a monster. Saya runs into the school, locking the door behind her, but the monster easily breaks through. The cello player appears and fights off the monster before grabbing Saya and taking her to safety in a classroom. There he tells her the monster is a chiropteran. The man kisses Saya, forcing her to drink his blood, then tells her she must fight.