勤め先で経理を担当する地味な社員・古東。部署では孤立気味で、気軽に手を出す存在として都合が良かった。会社で溜まったストレスを晴らす、ほんの息抜きのつもりだったのだが…。眼鏡を外し、服を脱いだ彼女は想像以上に魅力的で、久しぶりのSEXなのか感度も抜群。まるで自分がいい男になったと錯覚するほど何度も潮を吹き、絶頂を繰り返していく。‘このまま地味な人妻セフレで終わらせるには惜しい―’と俺好みに仕立てることを決心して…。

Koto is a plain-looking employee who works in accounting at his company. She's somewhat isolated in her department, making her a convenient target for casual encounters. It was just meant to be a quick way to relieve the stress accumulated at work, but… When she took off her glasses and clothes, she was far more attractive than he'd imagined, and her sensitivity was incredible, perhaps because it had been a while since she'd had sex. She squirted and climaxed repeatedly, making him feel like a real man. 'It would be a shame to let her end up as just a plain married woman's casual sex partner,' he decided, and began to mold her to his liking…