Milieu Rouge Tresor, most typically known as just "Milieu", is a Professor of Healing (the Mediwitch) at Gaius. She appears to have a soft spot for Lewin Randit, and is a sort of mother figure for him. She is normally calm and kind, but is very emotional, as shown in her outburst towards Professor Arshes when Chris is in critical condition. She has an older sister, named Cure-Noir Tresor. Her official title is "the Idigo Witch".
Milieu is about 15 cm (about 6 in) shorter than Professor Arshes. She's taller than the students, but not the tallest character. Her eyes are an amber color, but her hair color has so far been undisclosed. She has very long hair, and would probably be past her waist if she let it down. Milieu normally keeps her hair up in a sort of beehive style with a ponytail end. She has semi-long bangs that cover her eyes slightly. Milieu typically wears low cut shirts with an unattached collar and slightly corset style. She also typically wears a long skirt and a cloak. Accessory wise, she has a few rings, a pair of half-moon glasses, a forehead amulet, earrings, and a hair piece.