Birthday: March 3

Height: 160.3 cm

Blood type: A

At first glance, a seemingly kind, and selfless student, Mariya's true personality couldn't be further from that. A cunning, and incredibly sadistic boy who enjoys nothing more than torturing Kanako, or his twin sister Shizu, although he claims the treatment of the latter is because of his love for her.

Mariya attends the prestigious Ame no Kisaki Catholic girl's school, due to a rather silly bet thought up by the previous head of the school, who in actual fact is Mariya's grandmother who he deeply cares for, and holds in high esteem. Mariya keeps a rosary she once owned as a memento. The bet in question is that Mariya, and his twin sister each attend schools for the opposite gender, and if they can stick that out for three years, the winner shall become head of both schools. There is a catch, and that must be that nobody can find out their true gender. When Shizu comments that Kanako knew his gender, Mariya finds a loophole.

He is usually accompanied by his blunt and passive maid Matsurika, who helps him with putting his image together, including tying up his corset.