Two young men happen to kidnap their friend and demand ten billion won as ransom.
On a Christmas Eve, a lifeless body of teenage boy is found. The victim's revenge-driven twin brother checks himself into a juvie to hunt down the suspects.
Ji-woo, an outcast at a prestigious private school, meets Hak-sung, the school janitor who is actually a mathematical genius who defected from North Korea.
Min-ha and Sang-beom are a gay couple in high school. They go on a journey to the shore for their 100th day anniversary. Min-ha does not care what other people think and exhibits his affection towards Sang-beom in public. On the other hand, Sang-beom feels uneasy about this. That night, Sang-beom tells Minha a secret.
A village holds spirits of missing, deceased people. A search to find the missing bodies and discover the truth behind their disappearance occurs.
Young-eun who has a crush on her classmate, Min-su, realizes that her younger sister Young-ji and Min-su are in a relationship. Though she tries to suppress her emotion it’s not easy. One night, Young-eun witnesses Young-ji and Min-su having sex.
Ki-hyeok, moves to a new place to overcome his broken heart. There are no people like himself and no jobs are even available. One day, he meets Sangwoo in an application, who caught a cold. He fears that Sangwoo will leave him.