On the day his wife leaves for a trip, Gooro is left helpless at home, completely unable to manage housework. Without his usually skilled wife around, he struggles daily with cooking and cleaning. Then one day, an unexpected visitor arrives—his wife's older sister, Rie. She says she's come to help with the chores. At first, Gooro welcomes her gladly, but soon begins to feel uneasy about her behavior. Rie acts strangely forward, drawing close in an oddly insistent way. Her warm, soft big tits unsettle Gooro's senses and shake his resolve. Overwhelmed and flustered by her advances, he retreats to the bathroom, only to find no escape from Rie's seductive grasp. An unforeseen turn of events begins with this sudden visit.