Saya is a young girl who transfers into Yūma's class along with her twin brother Shinya, who is also a mage. She was initially mistaken for a ghost by Hachisuke after he met up with her one night by chance at school. Her magic wand is named Sanbach (サンバッハ, Sanbahha?) and takes the form of a violin bow. They have been serving the Shikimori family for generations. They never knew their mother because she is already dead. The reason is unknown.

-Wikipedia-