Minnie Cochran, another freshman student from Butterfly Hall who will run for President in the Student Council. Depending on whether or not you decide to run for the Student Council yourself and whether or not you suceed or if you study in the library with her help you may become good friends with her. Her romance has a very large role in the storyline proper, and you can even give her and Kyo Katsura advice about their love lives if you're close enough friends with either of them.
Minnie is a very dedicated student, responsible, smart and talented with magic. She's also good friends with Jacob Blaising, who will become a part of her convoluted love triangle later on in the game.
If you become a Treasurer you'll have a lot of interactions with her, she'll come to tell you about various events in the school year and explaining anything that you might be confused about if you ask.
On Ellen's route Minnie appears to give a secret warning about the consequences of breaking magical laws.