Heidi Augesvarer is a student at Musashi Ariadust Academy. She maintains a consistent partnership with Shirojiro Bertoni in both business and personal matters, and is rarely seen without her companion, the small fox-like Mouse named Erimaki. Heidi radiates a perpetually cheerful and uplifting demeanor, characterized by an ever-present smile. Though outwardly optimistic, she shares Shirojiro's strong tendency toward miserliness, with financial considerations frequently guiding her choices. Within the academy and wider Musashi community, she interacts among numerous classmates such as Toori Aoi, Kimi Aoi, Tomo Asama, Masazumi Honda, Futayo Honda, Suzu Mukai, Naomasa, Neito Mitotsudaira, Shirojiro Bertoni, and others. Her designated handle name is "Marubeya."