Miriam Hildegard von Gropius, also known as Miriam Hildegard V. Gropius, hails from Germany. She presents a bubbly and friendly personality, driven by an uncontrollable curiosity that compels her to approach every situation with a playful, game-like mentality. This often manifests as prankster behavior, causing trouble that sees her shunned by more serious peers despite her generally cute demeanor and absence of malice. Her extroverted nature fuels a love for interaction and conversation.

As a student at Yurigaoka Girls' Academy, she serves in the arsenal division, specializing in the technical aspects of CHARM weapons. Her speech carries a somewhat old-fashioned quality, occasionally making her a target for teasing from classmates like Moyu Mashima. Miriam wields the rare skill Phase Transcendence, but her reckless use of this ability frequently leads to rapid energy depletion, creating challenges in combat or on missions.