During my school days, my father remarried and formed a new family. His new wife had a daughter younger than me named Nene. While I was quiet and reserved, Nene treated me with great kindness. She was cheerful, innocent, sweet-natured, adorable, and had a soft, feminine body. Spending days alone with her gradually captivated my heart. One day, our parents left on a belated honeymoon, leaving me alone with my stepsister Nene for several days. That's when we found ourselves in an unexpected situation...