Sweet Blood(2010)

Sweet Blood

Sooho, a teenage boy abandoned by his parents, is living hand-to-mouth in a rundown apartment. His problems only get worse when an eccentric vampire king from another world takes an interest in his blood. After sacrificing himself to the nightly visits in order to save a classmate, Sooho realizes there's no easy way out of this strange bond. Is a life without pain too much to wish for?

(Source: Tappytoon)