The future Seoul, a city with the worst environmental pollution and the highest living prices. Shin-dong, the protagonist of the film, is helplessly living a repetitive and monotonous life, and is forced to find a new place to rent immediately by his landlord's unilateral notice. Unable to afford to move, his friend tells him that renting out a part of the house will complicate his rights and making it impossible for the landlord to evict him. Encouraged by his friend's advice, Shin-dong puts up an ad for rent. And when a strange newlywed couple shows up who want to live in the bathroom, Shin-dong impulsively invites them in.
Gi-eun and Gi-un take painkillers because of the spinal problems. They sleep day and night due to the side effects. In dreams, they meet other 'Gi-' characters and experience strange lives. Gi-young is an action star in B-movies. Gi-sook is an elementary school teacher. And other Gi-s who is a painter, truck driver, dancer, and a dentist etc... After all, she/he meets their “real“ self in their deepest dream.