Ruby Tojo is a witch from the human world who was part of a plot to destroy mankind as a response to a large garbage dump polluting her mistress' sanctuary. Her hate for humans stems from a car accident caused by a human drunk driver that took her parents' lives while the family was vacationing in the human world. Upon remembering the kind of love her parents had given her, she attempts to persuade her mistress to call off her plan but to no avail, as her mistress was bent on destroying the human world. She recuperated at Yokai Academy after her mistress is defeated and put to rest, and reappears when Tsukune becomes out of control as a ghoul, aiding Mikogami in sealing his abilities. She now resides at Yokai Academy as Mikogami's aide, and continues to work for him in the second manga serialization. Despite not being an official student, she receives permission to become a member of the Newspaper Club as its assistant advisor (though she prefers to take orders). Exclusively in the anime, a running gag involves her randomly switching positions to help the school. When asked why, she states "many many things" have happened, though it is believed these are orders from Mikogami as a debt of gratitude for providing her with a new magic wand. Her original outfit in the Witch's Knoll arc consists of a black sleeveless top with an exposed midriff and a long orange skirt, though she later switches to a gothic lolita outfit after she fully recovers from her injuries.