Due to my father's remarriage, I suddenly gained a stepsister. One day, when our parents left for their honeymoon, my sister stayed behind alone at home. That night, unable to resist, I reached out and touched her sleeping body. In that instant, she suddenly seduced me. It turned out she was a total masochist with an insatiably horny personality. That night, we crossed the line for the first time, forging a new, intimate bond between us.