When I was young, my parents remarried and had a daughter named Ichika. She adored me and was very close to me. Ichika has a friendly personality and gets along well with all of my friends, which made me happy. But who would have thought that she was secretly engaging in lewd games behind my back! My cute, beloved little sister! And she wasn't even aware of her own sexuality, so they took advantage of her! 'Let's do it too, big brother,' she said to me, and something inside me changed...
