Otto ni Ienai Gifu to no Kan'in ~Iya nanoni Wasurerarenaku Narisou~

This story involves a woman named Kashima Tomoka, who is the daughter-in-law of Kashima Takeo. She is bathing in a bathtub that has been spiked with an aphrodisiac. As the drug takes effect, she tries to suppress her sensual urges but fails. Takeo decides it's his duty to help Tomoka with her desires. He undresses and enters the room where she is bathing.