Majime ni Fujun Isei Kouyuu

Minami was raised in a strict environment that emphasized sincerity and seriousness, and she was taught to avoid romantic or sexual relationships. While dating a calm and mature senior coworker for three months, their relationship has remained completely chaste, with no physical intimacy. However, Minami hides a secret from her boyfriend—she reads erotic manga at home and has sexual fantasies about them together, making her a "good girl who secretly acts like a pervert." Her carefully maintained image is at risk when she accidentally leaves one of her adult manga at work.