From the introduction:
In this game you’ll begin with a single shared character - the apprentice wizard. You will create her as a group and she doesn’t belong to any one player - you’ll all play her at various times, individually and collectively.
Your apprentice wizard lives in your town - she even goes to your school! She knows everyone you do. She has the same teachers and shops in the same stores. She might even know you! Magic is very secret though, and non-wizards must never find out. Her master is an old wizard who lives in your town, too.
For now just keep in mind that you and your friends share this wizard’s apprentice, and you’ll share other characters as well.
During development this game was titled Dire Familiars and Apprentice, Wizard, Familiar.