It’s a scorching hot summer. Yusuke returns to his parents’ house after a long absence. His two older brothers are also home for the visit, bringing their wives — the two big-breasted sister-in-laws Yuri and Yuria. As the only single person in the house with no girlfriend, Yusuke finds the sight of the two married women relaxing in sweaty, defenseless outfits overwhelmingly stimulating. Unable to hold back any longer, he sneaks into Yuria’s bedroom… only for Yuri to notice.