Majime ni Fujun Isei Kouyuu

Minami is raised in a strict household, taught to be serious and sincere and prohibited from sexual relationships. Minami has been dating her senpai at work for three months, but their relationship is purely chaste where they haven't even kissed yet. But Minami has a secret that she can't tell to her calm and mature boyfriend… That is, she reads ecchi manga at home and has sexy dreams about them together, in other words she's "a pervert who's acting like a good girl"...!

And then, she accidentally drops one of her ero-manga at work...!?