新卒サラリーマンの相沢は、仕事に疲れ夏休みに田舎の実家に帰省した。工務店を営んでいる実家には、住み込みで働いている幼馴染のまのの姿。昔と変わらずボーイッシュで無邪気だけど、ラフな格好から覗く日焼け跡残るおっぱいにドギマギ…。夏の暑さにも増してジリジリと熱くなるチンポに我慢出来ずに一線を越え汗だくでハメまくった。SEXの時だけ見せる女っぽいスケベな反応とビンカン過ぎるまんこに勃起が止まらず射精。男友達みたいだなんて思ってたけど、もう昔の関係には戻れない…。

Aizawa, a fresh graduate working as a salaryman, returned to his hometown in the countryside for summer vacation, exhausted from work. There, he found his hood friend Mano, who was working and living at his family's construction company. She was as boyish and innocent as ever, but he was flustered by the sight of her tanned breasts peeking out from her casual clothes… Unable to resist the burning heat of his penis, which was hotter than the summer heat itself, he crossed the line and they had sex, drenched in sweat. Her feminine, lewd reactions that she only showed during sex and her overly sensitive pussy made him unable to stop his erection and he ejaculated. He used to think of her as just a male friend, but their relationship could never go back to how it used to be…