Visiting my friend's house, I find his younger sister home alone today. She's adorable and affectionate, flashing panty shots and cleavage without a care, completely defenseless. Usually I keep my distance around my friend, but today the tension fades, and I start feeling like she's secretly inviting me. Unable to resist, I finally make my move, and the mood gradually turns sexual. In the end, I realize our relationship has become intimate.