SSIS-998 I made a promise to my bratty sister that I would never penetrate her, and then asked her to be my sex practice partner... Hinawa Yotsuki

A stepsister named ‘Yuki’ from my father’s remarriage. My first impression was that she was arrogant and the worst, and I thought there was no way we could get along. However, after a certain event, our relationship became intimate. When my sister found out about my girlfriend, she said, 'You, of all people, managed to get a girlfriend? You probably have no experience, so if you promise not to insert it all the way, I’ll be your sex practice partner.' From there, we started with just rubbing genitals, then inserting 1 cm, just the tip, and gradually moved on to full intercourse. Eventually, I used her amazing body as a training ground and became addicted to the pleasure of sex!