Wall to Wall — Characters & Cast

To hold on to the apartment at any cost, because letting it go would mean admitting that everything he sacrificed — the relationship, the sleep, the 700 million won in loans — bought him nothing.

Begins as an ordinary striver celebrating the purchase of his first home in 2021. Over three years he loses his fiancée, his savings and his sleep, sliding from reasonable complainant to obsessive investigator to a man capable of severing a gas line and walking away from a burning apartment. His arc is not redemption but corrosion — and in the final scene, having survived, he returns to an empty unit, hears the noise again, and laughs.

Self-preservation and control: protecting what the ledger would expose, and steering a desperate man toward the outcome that serves her.

Presents herself as a fellow resident who understands Woo-seong's torment and can help him find the source of the noise, drawing him into the building's politics. Her real agenda emerges late, and she ends the film attempting to kill Woo-seong using the ledger hidden inside a stack of magazines — only to be stabbed to death in the struggle.

Grievance and vengeance within the building's hidden economy of blame — a man who has decided the system will never give him justice, so he will take it.

A neighbor whose interest in the noise dispute is far more personal than it first appears. He escalates the conflict from complaint to violence, and in the climactic struggle he is fatally wounded — but not before killing Eun-hwa, closing the loop on the film's mutual-destruction logic.