Michelle acts as lieutenant to Captain Agnès de Milan within the Imperial Knights of Tristain, exhibiting steadfast loyalty through her constant presence at her commander's side. Her appearance features violet hair (alternately noted as blue in some sources) cut to ear length and distinctive purple eyes. She displays a combative nature and wields considerable skill in swordsmanship, supplemented by training in firearms like muskets and flintlock pistols as part of her knightly duties.

During the episode "The Spy's Seal," Michelle infiltrates the Tristain Academy of Magic to steal items belonging to Queen Henrietta and Prince Wales from the headmaster's office. This theft prompts a search led by Osmond, who identifies her as the thief using a magic seal on her chest. The disturbance escalates, drawing Saito, Julio, and Louise to investigate Cattleya's room where Michelle is ultimately exposed. Her actions reveal a capacity for covert operations, though her specific motivations for the theft remain unspecified. Following her exposure, consequences occur off-screen as the narrative shifts to interpersonal conflicts between Saito and Louise.

Michelle's background and development beyond this incident are not detailed. Information regarding her origins, age, or further evolution across other seasons, films, OVAs, or spin-offs remains absent. Her documented role is confined to her duties as Agnès' subordinate and her involvement in the theft incident during the second season.