Kana marries a man with an adult son and builds a warm relationship with her adult stepson Yuichi. Yet her attempts to conceive with her sexually indifferent husband have gone nowhere, leaving her quietly frustrated. When her husband leaves on a long business assignment, she begins living alone with Yuichi. He steadily closes the distance and escalates from suggestive touching to open advances; unable to stop him, Kana is swept into repeated impregnation sex and creampies.