Marie is an assistant of the Velvet Room. Befriending Marie will help the protagonist realize the potential of the Aeon Arcana, eventually enabling him to summon the Persona Kaguya.

When Marie is first met, she seems to be a very cold and antisocial individual. She is sullen, cranky, sarcastic, irritable, very foul-mouthed and often prone to mood swings. She will not hesitate to voice her opinion or express her thoughts, regardless of how it would make everyone feel. The team is also weirded out when she politely apologizes, commenting that she never seemed like the type who would say sorry. 

When flustered or embarrassed, Marie tends to speak rapidly and insult the source of her embarrassment, like "shutupIhateyouyoustupidjerk!"

English Voice- https://www.youtube.com/watch?v=6s3xjCW7_Zw