Shidou, Mariya

祇堂鞠也

At first glance, Mariya appears to be a kind and selfless student, but his true personality is the complete opposite. He is a cunning and incredibly sadistic boy who takes pleasure in torturing Kanako or his twin sister, Shizu, though he claims his treatment of the latter stems from his love for her.
Mariya attends the prestigious Ame no Kisaki Catholic girls' school as the result of a rather silly bet devised by the previous head of the school, who is actually Mariya's grandmother. He deeply cares for her and holds her in high esteem, keeping a rosary she once owned as a memento. The bet stipulates that Mariya and his twin sister must each attend schools for the opposite gender; if they can endure this for three years, the winner will become the head of both schools. There is a catch: no one can discover 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 maintain his image, including tying his corset.