I hadn't paid any attention to her before, but before I knew it, my sister's body had developed into a woman's, and I couldn't help but get excited... My sister always stretches at home, and she wears a miniskirt. Her panties occasionally peek out... And she begs me, "Big brother! My shoulders are stiff!" and I can't help it. One day, while I was taking a shower, my sister barged in completely naked, and as always, she begs me, and my crotch starts to swell... Whether she's innocent or knowing it, these are four stories of me being tempted by my sister's provocative body and doing naughty things.