One day, the tax office receives a phone call. It is an accusation that the inn where Nanao works as a hostess is evading a large amount of tax. Tax officials Oiwa and Inoue immediately head to the hot spring inn where Nanao is staying to investigate undercover. Nanao, who notices that the officials are staying overnight at the hot spring to investigate undercover, plots to somehow evade the tax investigation by playing a very erotic trick on the officials in a see-through yukata.