After losing her husband, Mami returns to her parents' home to live with her beloved daughter, Yui. One afternoon, while she's out, a burglar breaks in. The intruder turns out to be Sugaura, a man she works with part-time, driven to theft by overwhelming debt. When Mami returns home, she catches Sugaura rummaging through her belongings. In that moment, the tension snaps—everything changes.