One day, my younger sister suddenly showed up at my apartment where I lived alone and declared she would move in with me! She deeply cares about me and starts helping around the house like a maid, taking care of cooking, laundry, cleaning—everything. On top of that, she acts all cute and clingy, hugging me tightly and even kissing me. My rational mind gradually breaks down, and despite being siblings, our relationship turns increasingly erotic. Living together in this loving, intimate way feels even better than I ever imagined, sending my life on a sudden path toward overwhelming happiness!