Dongsoo's a loser, no doubt about it. He's unreliable, unemployed, and unlikely to get laid any time soon. At least, until he runs into Geumsil on a train to Seoul. Short skirt and and boob window aside, she's way out of Dongsoo's league. But, that all changes when an accident on the train embues Dongsoo and some other passengers on the train with a thousand years worth of sexual spiritual energy. The thing is, there's only one way to release the energy. Time to hang out with your yang out.