During summer break, Haruma is sent to stay with relatives in the countryside after his parents are transferred overseas. He reunites with Kaoru, his childhood friend and older cousin, whom he hasn't seen in years—only to discover she has matured into a stunning, confident woman. The hot summer air intensifies as her sweat-slicked body and seductive gaze draw him in. One day, she suddenly declares, "If you're still a virgin, I'll take it for you," and their relationship quickly spirals into something far more intimate. With no friends around in the rural town, Haruma's summer becomes a steamy, sweat-drenched affair—days filled with close, physical contact and passionate encounters with his H-cup busty cousin, as they crave each other both emotionally and physically.