One day, the bodies of the dull virgin brother Shinji and his gal sister Emiri are swapped. Shinji, who has become a gal, engages in lesbian kissing at his sister's workplace, and is forced by a man to lose his virginity (virginity?)! In the confusion between the brother and sister, his sister finally asks him to accept her boyfriend, and he gives her a blow job. With mixed feelings, the brother has loving sex with his sister! What will happen to the two of them? What will their fate be?