Reina Mito functions as the homeroom teacher for class 2-5 at Kamui Daimon Comprehensive Academy while commanding the Jenock Faction. She features light-brown hair secured by two back bowties with a single hip-length strand framing her left cheek, dark-brown eyes, and standard attire of a black jacket, tie, skirt, and boots. Her father, scientist Eisuke Mito, ties directly to the series' core conflicts, profoundly shaping her motivations. During her debut, she introduces transfer students Arata Sena and Hikaru Hoshihara to their class. She subsequently escorts them to the control pod room, detailing essential concepts like War Time, Second World, and the Experiment Realism Project. Upon arrival, she assigns both recruits to Haruki Izumo's First Platoon, briefing the unit on Operation Seize Oasis 3 during LBX transportation. Her tactical leadership includes rejecting Gendou Isogai's proposal for the Second Platoon to capture Eldband until a viable strategy emerges, later approving a Joint Operation between both platoons. She commands the First Platoon to confront Val Sparos despite Sakuya Hosono's protests and reluctantly permits Seredy Kreisler to instruct her class, monitoring his session. Post-lecture, her exchange with Seredy implies his awareness of her father's status, prompting tactical resource shifts: assigning Orvane to Gendou and Val Sporos to Kaito Fuujin. A critical juncture unfolds when she discovers her father within Second World's mainframe. During her rescue attempt, Seredy intercepts her with his D Ezeldee unit. Detecting Arata Sena's proximity, he redirects to pursue Arata and Kyouji Itan, threatening to shoot her unless she complies. Her given name Reina combines the characters for "the tinkling of jade" (玲) and "apple tree" (奈); her surname Mito derives from "beautiful" (美) and "metropolis" or "capital" (都).