Coming home, I'm shocked by an unexpected sight. A school girl lying on the sofa wakes up, revealing her slender legs, her skirt riding up to expose white panties that instantly stir my emotions. She calls out, "Onii-chan!"—to my surprise, she's my new stepsister from my parents' remarriage. From that moment on, my life becomes a series of seductive encounters with her, drawing us closer each day. Eventually, I end up penetrating my sister's pussy.