Father-in-law used to be energetic in both work and play, but after an injury, he suddenly aged and lost his vigor. Seeing him in this state, young daughter-in-law Tsubasa feels deep concern. One day, the father-in-law confesses, "I've had erectile dysfunction and no desire lately, but seeing Tsubasa's naked body made me feel aroused for the first time in ages." Tsubasa finds herself torn between a desire to help her father-in-law and the guilt of betraying her husband. In an attempt to restore his erection, the father-in-law takes an extreme sexual approach—one that spirals into something far beyond expectation.