The Moment When a Fox Becomes a Wolf

From RC-SCANS:

Gook Eun-Song is your average high school girl... that is until her attractive younger sister stole the man she had a crush on. Depressed, Eun-Song purchased a bottle of alcohol and crawled into a supposedly cursed closet in her father's furniture store.
Yu Ha is your average typical bad boy. Going insane over one article in magazine, he even broke traffic regulations while drunk just to end up being chased by a couple of police officers.

Oddly enough, he also ended up in the same closet where Eun-Song is asleep from drinking too much. Yu Ha ends up sleeping in the cursed closet with Eun-Song by his side... just to find out the next day, their bodies have been switched!

Can anything else possibly go wrong for our poor heroine?