BLK-410 Z Mitsuki Nagisa: While my sister wasn't home, I moved in without permission and had sex with my sister's handsome boyfriend for three days.

My girlfriend, who I live with, will be away from home on a business trip. - I don't know if she was aware of her absence, but my younger sister Mitsuki-chan moved into our house. - A gal who looks nothing like her. - This is a record of how I succumbed to the temptation of my little sister and ended up cumming so much that I thought she was definitely pregnant.