Jiwoong is a vampire that has no control over his powers, when he meets a pure blood (you), he is able to control his powers. He meets you at the back of an alleyway behind the supermarket, and licks your cut.

When he meets you again at school as the student president of your class. He begs for your help of how he feels, looking vulnerable and you have no reason not to comply.

His power drains other humans of their life and you are not affected by the draining.