Kamakura has shut himself away in his apartment, letting garbage pile up around him until he is living as a recluse in a hoarding house. His isolation began after a traumatic incident at work where he was publicly berated by his boss, culminating in a violent confrontation that left him unemployed and deeply depressed. Resigned to his fate as a hikikomori, he has stopped engaging with the outside world.

This stagnant existence is interrupted when a baseball flies through his window. The landlord is alerted to the broken window, and when Kamakura does not answer the door, a neighbor named Katsuyoshi climbs in through the balcony to investigate. To Kamakura's horror, Katsuyoshi and the landlord discover the shocking state of his trash-filled home. On the verge of eviction, Kamakura is surprised when Katsuyoshi intervenes, offering to help clean the apartment instead. Katsuyoshi insists that Kamakura stay with him in his own clean apartment while the work is underway, and Kamakura reluctantly agrees.

The story is set almost entirely within the confined spaces of two neighboring apartments, creating an intimate and pressurized environment. As they begin the enormous task of cleaning out the hoard, the two men start to open up to one another. Kamakura, who is initially meek and ashamed, slowly begins to heal under Katsuyoshi's patient but firm guidance. For his part, Katsuyoshi is not just a kind stranger; he is dealing with his own past trauma and personal reasons for wanting to help, which are gradually revealed as the cleaning progresses. The narrative follows their journey from strangers to something more, developing into a sweet slice-of-life romance about moving forward one trash bag at a time.

Notable narrative arcs include the initial shock of Kamakura's living conditions being exposed and the subsequent landlord crisis. The physical act of cleaning the hoard serves as a powerful metaphor for emotional and psychological cleansing. A major plot point involves the two men navigating their growing attraction in close quarters, including awkward and intimate moments that complicate their arrangement. The story, which is collected in a single volume comprising six chapters, concludes as both characters confront their pasts and make tentative steps toward a shared future, having found an unexpected partner in their mutual rehabilitation.