Following a tragic fire that shattered the Mitarai family years ago, Anzu, the eldest daughter, witnessed her mother's heartbreaking plea of guilt. With the family's downfall leading to her parents' divorce, Anzu, now known as Anzu Murata, toils at a cleaning company to support her ailing mother. As fate would have it, she lands a job at the household of Makiko Mitarai, her father's second wife, who exudes an impeccable facade hiding her aversion to cleaning. Convinced of Makiko's involvement in the past tragedy, Anzu adopts the guise of 'Shizuka Yamauchi' to uncover the truth and clear her mother's name. Yet, as she delves deeper into her investigation, Anzu must tread carefully, knowing that one misstep could jeopardize everything she holds dear.