The Mirror Girl - 鏡の少女

Izumi Hannei, A mysterious girl from another world gets banished from her homeland and is forced to live in a mirror belonging to the bathroom of Keizo Tezuka, a quiet boy on his last year of high school. The two eventually meet and develop a strange connection. As time goes by, they grow closer and closer, not counting the pane of glass between them. Keizo and Izumi decide on working together to get her out of the mirror. In order for her to escape, Keizo must learn the arcane magic of Izumi's world from scratch and maybe uncover some not-so-well-kept secrets and lore along the way.