A comedy about the sexy and lovely growth of a teenager from a 16-year-old girl's point of view.

A street hooker named Hyeon-ah (Jeon Yoo-jin) is locked up topless in the pension of a man named Jeong-ho (Heo Dong-won) who saved her from her pimp's abuse and beatings. She was locked up for no reason and every time she struggles against him, he hits her. A couple visiting the pension find Hyeon-ah and the man who wanted to rape her is killed by Jeong-ho. Hyeon-ah tries to run away from him but realizes she has nowhere to go.

Ki-Chul drives his friends out to a resort situated by an abandoned coal mine. His father owns the resort. When they get there, they cross paths with a spooky man who warns them about the coal mine. Later, the friends find themselves in a desperate situation and enter the tunnels of the abandoned coal mine. Will they ever see the light of day again?