Mai Hoshino is a central character in the anime Room of Guilty Pleasure, where she is portrayed as a student with a notably defiant attitude toward her teacher, Mamoru Sasaki. The narrative establishes her as one of his most challenging pupils, contributing to his constant state of being overworked and disrespected in his professional life.

Her role in the story is triggered by a supernatural or dreamlike event. After hearing a mysterious announcement late at night inviting him to select a preferred student from a transformed shoe locker panel, a beleaguered Sasaki jokingly names Mai. Following these instructions, he finds her waiting for him in a classroom, where her demeanor shifts from her usual defiance to one marked by a visible blush as she meets his gaze. This encounter marks the beginning of a forbidden relationship, driven by the story's premise where anything is allowed within this secretive "Guilty Pleasure". Her character is voiced by Amai Miruku in the Japanese version of the series.