Komatsu An, a former company president's secretary who remarried a businessman, sincerely cared for her stepson as his stepmother, always showing kindness and emotional support to him despite his reclusive lifestyle even after reaching adulthood. One day, trying to encourage him, An suggested giving him a massage. During the intimate contact, she was shocked to feel her son's body growing unexpectedly hard and large. Confused yet unconsciously aroused, An began to wet herself. Excited by the situation, her stepson begged her to let him ejaculate inside her...!