One day, a sudden accusation call comes from the tax office. The allegation? The hot spring inn managed by Nao is involved in large-scale tax evasion. Shortly after, tax officers Oiwa and Ikuo begin an undercover investigation at the inn. Noticing the two staying on-site to conduct their probe, Nao approaches them in a sheer yukata, setting up bold and seductive traps. Surprised by her appearance and actions, the officers devise plans to avoid exposing the tax audit. As the investigation unfolds, the secrets of the inn, Nao's hidden truths, and the fate of the tax probe draw the two men closer to her in increasingly intimate ways.