The story takes place at the door of an ordinary apartment in a modern city. 38-year-old Ayano, evicted by her landlord, stands outside her son's home, dragging her only suitcase. She has been divorced for many years and has raised her son alone, but the two have not seen each other for a long time due to various reasons. Now, with nowhere else to turn, she has no choice but to seek refuge with the child she once raised alone.

Ayano wasn't sure if her son would accept her. She stood outside the door, her finger hovering over the doorbell, hesitating whether to press it. Her suitcase contained all her belongings—a few changes of clothes, some old photos, and a yellowed photo album. The night wind was cold; she was only wearing a thin jacket, and her legs, encased in nude pantyhose, trembled slightly in the chill.

The moment the door opened, she faced a difficult question: what identity should she have in her son's life? Was she merely a mother seeking refuge, or was she willing to offer more? She had nothing left; her only remaining assets were herself—her body, her labor, and her companionship.