In her fourth year of marriage, wife Sakura Sayane finds her sexual relationship with her husband dwindling, leaving her increasingly frustrated. One day, she visits her father-in-law's house with her husband and discovers the elderly man suffering from advanced dementia, unable to even recognize his own son. Worried about his condition, Sakura decides to take over his care. The father-in-law claims he has taken up painting as a hobby and asks her to be his model. Though hesitant at first, Sakura agrees—only to find his eyes fixated on her voluptuous hips as he begins to paint. Unexpectedly, she feels arousal building between her legs, and the father-in-law, noticing her wetness, exclaims with delight, "Now this is art!" Drawn in by his brushstrokes and gaze, Sakura soon finds herself falling into deep, forbidden desire.