Rieko, who remarried Kenichi and has two stepchildren with him. However, Rieko's voluptuous and obscene body strongly stimulates her teenage stepsiblings, Kenji and Masao. Strangely enough, Rieko falls into a sexless situation as she misses Kenichi due to his night shifts. Then the brothers start fighting over Rieko, trying to make her their own. Masao, who innocently shows off his erect penis and demands sexual services, and Kenji, who watched this, later says, 'Do it with me too,' demanding her body. Thus, the brothers' desires become increasingly twisted as they pursue Rieko...
