酔っぱらった上司の北条を家まで送り届けるよう命じられた藤田。そこで出逢った妻の麻妃が密かにオナっている痴態を目撃してしまい…。だが夫ともご無沙汰で我慢できなかった麻妃は、「擦るだけなら」と素股で互いの性器を押し付け合い絶頂を繰り返すのだった。誰にも言えない秘密を共有した2人は、こっそりと身体を重ね続け、いつしか膣内でも性器を擦り合う関係にまで発展して…。

Fujita is ordered to take his drunk boss, Hojo, home. There, he encounters Hojo's wife, Maki, and witnesses her secretly masturbating… But Maki, who hasn't had sex with her husband in a while and can't resist, agrees to "just rub" and they begin to rub their genitals together, reaching multiple orgasms. Sharing a secret they can't tell anyone, the two continue to have sex secretly, and before long, their relationship progresses to the point where they rub their genitals together inside each other's vaginas…