ZUKO-098 My serious sisters got influenced by our relative's gal and now they're making babies

Living with my sisters who are honor students and solid. However, the peace disappeared when a relative gal came to stay. I have to bring my sisters various erotic knowledge, and I have to keep making ridiculous demands such as showing my masturbation to the gyaru and my four sisters who have been completely respected, and playing prostitutes in the bath. Girls who are serious at heart and can't be touched once they become erotic... I wish you good luck.