Recently my dad remarried and my stepmother's daughter Himari became my little sister. I was happy to have a cute little sister, but in fact Himari is a perverted girl who loves dicks and when my mother isn't looking, she shows me her panties and seduces me, which is a problem. One day, my stepmother went on a trip with a friend, and when I was left with only men in my house, Himari took the opportunity to approach me...