Winter 1988 - Middle school student Jin-Woo lives with his unemployed alcoholic father and his mother who frequently attempts to run away from home due to her unhappiness with her husband. Jin-Woo's older sister does whatever she wants and fumes at her mother for the life she lives. Jin-Woo feels sorry for his mom who has to support the family alone and starts to work as a newspaper delivery boy. At the newspaper distribution plant, he meets another boy named Chang-Geun who works hard to save money. Jin-Woo learns from Chang-Geun things like how to smoke, drink alcohol and how to deal with girls. Jin-Woo learns about life through Chang-Geun.

On a live music radio show, a letter arrives from twenty-three years in the past. Through the letter, the first love and friendships of five friends are revealed.

Mi-ja, who has been taking care of a retired teacher, Ms. Park, invites several of her former students to her house 16 years after their graduation. Since the end of her teaching career, Park has been residing in the countryside, suffering from an illness while an ex-student, the kind and pretty Mi-ja cares for her.

An old man has trouble connecting with his young grandson that recently moved in. But then there are a series of mysterious attacks on the elderly, and the grandpa-grandson duo decide to investigate together and bond over the experience.