Kuroko Tetsuna, a girl with a gifted skill for playing basketball is forced to leave her friends to attend her uncle's school. Said Headmaster of the school found out that she was living alone and threw a fuss about how her niece wasn't getting cared for. Having a family filled with vampire hunters had its perks, because she obtained their ability to not age anymore. Though being immortal, Tetsuna is considered fragile for she can get tired easily except of course when playing the sport she loves.