i returned to my parents' house for the first time in a while. i used to get along well with my sister yayoi when we were little, but we became estranged after my rebellious phase. my sister, whom i hadn't seen in a long time, had grown up in a strange way. but maybe she hasn't quite become an adult yet, her panties are showing a lot... no, is she showing them off...? a single piece of cloth digging into her crotch, unable to cover her big ass. there's no way i'd get horny over my sister... in the midst of all this, my parents went on a trip. even at my parents' house, where it was just the two of us, the panty shots didn't stop. my sexual desire for my sister is also unstoppable now. once i put my hand on her, that's it, sex & sex while my parents are away. i thought my sister was supposed to be this cute... supposed to be this erotic... even though i thought that, i kept fucking her.