In Sector 7, an underwater oil field located south of Jeju Island, Hae-jun is working as a marine equipment manager on an oil prospecting ship called Eclipse. Joining the crew later is Jeong-man, a former colleague of Hae-jun's father, assigned to Eclipse as captain. Though his job is to oversee the withdrawal of the ship, he suggests conducting some drilling one last time.
In his 10th year at college, Eun-sik is part of a nearly ideal campus couple with swimming champ Kyung-ah. While their three-year relationship is solid, Eun-sik struggles to get to the next level with Kyung-ah; despite the help and support of his friends, he can’t manage to get her into bed.
A mosquito from Transylvania finds its way to Seoul where it bites Na Do-yol, a corrupt police officer. Soon after he begins to develop a thirst for blood, and finds out that he has vampire super powers whenever he becomes sexually aroused. When Do-yol's past misdeeds come back to threaten his partner and girlfriend, he decides to clean up his act and sets out for revenge.