Recently, Yuka has become close friends with her coworker Kouki, a student. As they go out drinking together, she can't help but feel a subtle anticipation... Little did she know that this sudden spark would lead her to give in to his passionate desires, starting a secret affair limited by time. Since then, whenever she finds a moment between her busy days filled with housework and childcare, she meets up with him to continue their illicit encounters, indulging in pleasure despite the short amount of time they have together. Her longing for quickie sex during work hours becomes an unspoken routine, leaving her wet and aroused even while on the job.

最近、パート先の学生・黒井と仲良くなった優香。ほのかな期待を抱きながら、二人飲みに出かけると…。家事、育児に忙殺される日々に訪れた突然のときめきに、子宮の疼きを抑えきれず、彼の熱い想いを受け入れ、時間限定の不倫を始めてしまうのだった。以降、仕事の合間を縫っては、場所を選ばず不貞を繰り返し、限られた時間の中で快楽を貪る優香。日課となった時短交尾への期待に、いつしか股間を濡らしながら仕事を…。