Yui has been living away from her family home, but due to recent social circumstances causing her part-time job to suspend operations, she's had no choice but to return home. Her mother, who divorced because of her father's domestic violence, remarried after Yui moved out. Although Yui had met her stepfather several times before, she always felt uneasy about their relationship. Now, her mother suddenly announces a business trip and leaves the house. Yui is left alone at home, trapped with her stepfather, forcing her to confront the painful memories she'd tried to bury.