Her younger sister, Riri, is cuter, more innocent, and super dope than her. But ever since she met her, she's been curious about one thing...the summer fashion of modern girls that exposes a lot of skin. Furthermore, when she was relaxing at home, her pussy muscles were clearly visible through her skirt. Moreover, when she bends over without a bra on, you can't help but notice her lucky lewd body, where you can see her breasts and even her nipples. Even though she knows it's no good, she loses all reason at the defenseless temptation, and before he knows it, he's massaging her breasts and goes wild. Even though she is nearby, she is swallowed up by her immoral pleasure and overheats violently until she gets heatstroke. Memories of a summer of people who couldn't stop their sexual desire for each other and went crazy...