Seoul 2022, where 'eating alone' has become the norm. The TV features news reports about serial killers that target women living alone.
Hyun-Jung (Choi Ji-woo), a woman living alone nervously watching the news. Seung-Jin (Jeoung Dong-won), a middle schooler trying to raise his failing grades by doing volunteer work. Hyun-Su (Lee Yu-mi), a woman trying to find a friend of the opposite sex through a dating app. Hoon (Choi Min-ho), a man who finds a mysterious letter with written instructions to find the woman who penned them. Gee-jin (Pyo Ji-hoon), an unemployed man with a one-sided crush on the stewardess next door. Yeon-jin (Ha Da-in), a musician and part-time worker at a convenience store who lives a crappy shitty life dealing with rude customers daily.
These six people's lives intersect in unexpected and disturbing ways over the course of four days.