You may meet Theodore or Theo, as he introduces himself, in the Velvet Room. The “may” part depends on you.
As the female protagonist you can choose a male or female attendant when you first meet Igor. Pick the male one and Theodore dispatches side quests and fills out the Persona compendium. Interesting, but will Theodore have the same relationship as Elizabeth did with the male protagonist?
Here’s another Persona 3 Portable video featuring Rio, one of the new social links on the female protagonist’s path.