When a young gang leader seems to be just a bit too stupid to effectively carry out his daily tasks, his superiors order him to go back to school for his high school diploma. Posing as a 19-year-old, he soon learns that the school is even more corrupt and vicious. Wrath is unleashed.

A mobster must complete college and spend some time as an ethics teacher in order to receive a promotion to a coveted territory.

Jang Choon-dong is a traffic officer who aspires to become a homicide detective. He is assigned to go undercover to infiltrate a gangster network. Meanwhile, Lee Joong-dae, a member of Kwang-seob's gang, goes undercover himself by joining the police force. Joong-dae tries hard to gain favor with his squad leader in an effort to expose Choon-dong's identity.

Despite their different family backgrounds, four friends grew up together in the wearisome years of the 70s. But as time goes by, each of them takes a different life path.

In order to bust a money laundering ring, the cops must work undercover at a hostess bar. Zaniness ensues as we witness policewomen masquerading as hostesses, detectives masquerading as waiters, and other similarly awkward role-reversals.

Il-bum works hard to pay off his daughter’s hospital bills but one day gets fired for being wrongly accused as a molester. After series of failures, Il-bum finds a job at a PR company which provides free entertainment to old women in exchange for buying their products. Il-bum feels shameful to play dirty tricks on old women but he has no other choice. Despite his initial concerns, Il-bum starts to feel a sense of worth entertaining old women. A new team member, Ok-nim joins and Il-bum becomes a good friend to her, making her feel warm and safe which she never gets from her own son. But, the joy of their friendship won’t hold long when Il-bum’s debt reaches beyond help.

11 members of an internet suicide site gathered in an abandoned school. They included a former baseball player who retired because of his injuries, a cancer patient whose death was declared, and a high school girl being pessimistic of her school score. While having the last supper after completely preparing the equipment and method for their suicide, they listen to each other's stories.