After arguing with his wife, Ryota comes home intending to make up through sex. Without looking at the face of the woman asleep under the covers, he mistakes his sister-in-law’s fleshy ass for his wife’s and pushes straight inside. Her pussy feels tighter than usual, driving him to pump a huge load into her. He asks for another round—only to discover that the woman is not his wife but her older sister, Akari.