One day, Akimi is asked by her husband to take care of her father, Toku, in place of her sister, who is not feeling well. Akimi is scolded by her sister-in-law, who acts like a mother-in-law, but Toku, who is being cared for by the beautiful Akimi, gets an erection while bathing him. Akimi feels stressed about being unfamiliar with the caregiving, but when she sees his penis, Kokoro is filled with a sense of fulfillment...