In Mobius, Marie is a 2nd Year student and classmate of the protagonist.
She is an exceptional honors student with a gentle demeanor that makes her approachable.
Even while participating in the Go-Home Club's occasionally dubious activities, she watches over the main characters without too much prying. This is particularly true for the main character, whom she supports as a close friend.
She is destined to be caught in the conflict between the Go-Home Club and the Ostinato Musicians.