This novella depicts the hopeless love between Shin'ichi Nakaoka, a 25-year-old high school teacher, and Sachiko, a 23-year-old woman working at a "soapland" sex establishment. It is the summer of 1987, and Sachiko?with whom Shin'ichi had sex just once, during a visit to her workplace a half-year earlier?comes to ask him for a ?50,000 loan. He provides the money, and a short time later she ends up living in his apartment.
She explains that she has two sons, age five and three, living at a foster care facility in her hometown; her husband is a gangster currently serving a prison sentence. Summer vacation arrives, and Shin'ichi and Sachiko take a trip to her hometown, embarking on what turns out to be a month or so of a hellish flight and the core of the story. They take her sons out for a trip to the beach, later returning them to the facility. Sachiko is changed after this, though, and Shin'ichi responds with escalating violence on his part. He promises that he will make her his wife, going so far as to buy wedding rings; just days later, though, he abandons the plan in the face of opposition from his parents and siblings. That night Sachiko slashes her left arm with a razor. She refuses to go to the hospital for treatment, and Shin'ichi uses an ordinary needle and thread to knit her wounds together, reaching a sexual climax as he does so. This work takes a painstaking, serious look at how the impulse for violence against the weak takes root, grows, and leads even to pleasure for the inflictor.