TV-Series
Description
Moyu Mashima attended Yurigaoka Girls' Academy from kindergarten, displaying high aptitude as a Lily early on. The Garden harbored significant expectations for her future following exceptional junior high combat performance. Despite recommendations to join the Lily Department, she selected the Arsenal Department instead. During her high school advancement interview, she explicitly declared her core identity as an Arsenal, stating: "I came to Yurigaoka to become an Arsenal. While I may act as a Lily occasionally, at my core, I want to be an Arsenal." This choice elevated the Arsenal Department's status, previously seen as a fallback option.

Within the Arsenal Department, Moyu earned high respect and became a role model. Across the wider academy, however, she faced negative perceptions, often labeled a "mad scientist" or "weirdo." This stemmed from research extending beyond ordinary comprehension and controversial first-year high school projects.

Her primary research focused on developing "Mind-coupled CHARMs," classified as fourth-generation weapons interfacing directly with the user's brainwaves. These carried significant risks, including potential brain damage and incapacitation if mishandled. Adhering to Yurigaoka's unspoken rule requiring Arsenals to field-test their own creations, Moyu consistently performed initial combat trials personally. Though Lilies like Hasebe Touka and Banshoya Ena participated in later battlefield tests, the technology remained incomplete. Her recognized masterpiece, the GC-17 Vinst Lilie, possesses a specialized design restricting usability solely to Shiba Tomoshibi.

Moyu collaborated extensively beyond Yurigaoka. Dispatched to Ludvico Private Girls' Academy by the Inter-Garden Conduct Board, she customized the CHARM Dainsleif Carbine and designed its enhancements. Around this time, Funada Kiito of the newly formed Legion Hronesnæsse at Odaiba Girls' School approached her. Seeking customized CHARMs tailored to each member's unique capabilities, Kiito connected via Nagasawa Yuki. Moyu subsequently designed and refined specialized CHARMs for the entire Hronesnæsse unit.

In stage play continuities, Moyu joined Legion Sanngriðr. Within anime continuity, after the Yuigahama Nest's destruction, she formed a Schutzengel partnership with Miriam Hildegard von Gropius, symbolizing a deep mutual bond. This partnership was later publicly celebrated and documented in media reports.

Their relationship involved frequent collaboration and camaraderie, appearing together during Huge encounter data collection and workshop activities. Miriam often expressed concern over Moyu's workaholic tendencies, while Moyu affectionately used the nickname "Gropi." Their dynamic included lighthearted banter and mutual reliance, culminating in their formalized Schutzengel contract commemorated in a widely publicized photograph resembling a wedding announcement.

A manga spin-off further detailed their interactions, showing Moyu resting her head on Miriam's lap during breaks and agreeing to a personal outing. When a sudden tech conference caused Moyu to miss their plans, Miriam experienced visible loneliness. This led to a reconciliatory moment where Moyu apologized and shared pancakes with her, an incident captured in the academy newspaper.

During critical missions, Moyu provided strategic technological solutions. She analyzed the Rare Skill "Charisma" and its role in Huge evolution, reporting findings to academy leadership. Confronting a mega-Huge, she developed a "bug" code injected via Yuyu's Dainsleif, enabling the creature's non-combative elimination. She later determined Riri Hitotsuyanagi's unique suitability for a high-risk operation against an ultra-class Huge, overseeing the mission parameters.

Moyu Mashima is 17 years old, born on September 19, with a height of 164 cm and weight of 52 kg. Her surname combines "真" (real/genuine) and "島" (island), while her given name incorporates "百" (hundred) and "由" (reason/cause).