After landing a job in my hometown, I returned home and my life took a dramatic turn. The biggest change was my parents' remarriage, which meant I gained a stepsister. To make matters worse, my father's transfer was announced three months ago, leaving me and my stepsister alone in this house. My stepsister, Hina, dropped out of university and has been staying home ever since. One sweltering summer day, the air conditioner in her room broke down, leaving me drenched in sweat. Seeing this, Hina's pent-up desire exploded, and she transformed into a wild woman, pouncing on me and demanding, "Brother, just lend me your cock!"