Ms. Dorothy, known as Tome-san in the Japanese version, is a school staff member who works and owns Duel Academy's card shop. She actually has very little knowledge of the rules of a real Duel.
Ms. Dorothy gave Jaden Yuki "Transcendent Wings" and "Winged Kuriboh LV10," as a reward for him helping her out earlier in the episode. Since then, Ms. Dorothy has become well acquainted with Jaden and his friends. It is sometimes hinted that she and Chancellor Sheppard are romantically attracted to each other.
In the dub, her nickname is "Miss Duel Academy."
In Yu-Gi-Oh! GX Tag Force, after beating the game with a number of characters, the player may face Ms. Dorothy dressed as "Dark Magician Girl" at the school festival.
The card shown in her Deck in the anime is "Marshmallon".