Mayuri is the home economics teacher at Ririsa and Masamune's school, as well as the supervisor of the school's cosplay club. She is quite a beautiful and attractive woman who was once considered one of the four "goddesses of cosplay", but Mayuri had to temporarily voluntarily go into hiding due to the fear that her cosplay interests would ruin her career as a teacher and respected member of society.
Mayuri's exact sexuality is never commented upon, however it is known that she likes girls. She often half-jokingly rants about Ririsa's attractiveness and in Chapter 161 enters into a lesbian relationship with Eri, her best friend and fellow cosplayer.