Mei, also known as "Mee-chan", usually appears to be a stubborn girl who tends to be industrious and competitive despite her standoffish nature. Mei secretly desires to be friendlier, but finds it difficult to express her emotions. This is due to an event in her past during elementary school when she was unanimously voted to be the class representative. Before long, the students in her class started shirking their own duties, in effect giving Mei all the work to do herself. After this treatment from her peers, Mei had lost faith in the intentions of people and distanced herself from others. When greeted by other students, Mei will usually not respond and just keep walking, apparently completely ignoring them, but is in fact too shy to engage in conversation. Mei has very little tolerance for school politics and sees school events for the waste of time that they are. Mei and Mutsuki have known each other since childhood, though Mei does not act like it.

After initially trying to organize the work of the student council, Mei gets inadvertently involved with the council's initial projects after Manami becomes the president, such as remodeling the student council room or helping to organize the inter-school dodgeball tournament. Mei is eventually inducted into the student council as the treasurer.