Kanan and Yuzuru know their relationship is twisted. Their parents were usually away, leaving the siblings virtually alone together. Neglected by his parents, Yuzuru became a shut-in, while Kanan spoiled him with all the affection he lacked. When he once told her he was aroused, she agreed to relieve him, and the favor continued again and again for ten years. Now both are adults, yet the warped relationship remains, supposedly limited to outercourse. But she can no longer hide how wet and responsive her body has become, and when her brother secretly slips in only the head of his cock, she cannot bring herself to refuse, crossing the line into incest and a creampie.