Yuuna Yuuki balances two lives in the year 300 of the divine age. By day she's an unremarkable second-year middle schooler, but her afternoons belong to the Hero Club, a peculiar organization tasked with confronting the Vertex: otherworldly threats that emerge without warning. What should be impossible coexists with the mundane as she and her clubmates transform into magical warriors whenever danger appears, fighting to protect a world most people don't know is under siege. The burden of secrecy weighs differently on each member. Some find strength in their bond, while others wrestle with what they've sacrificed to stand on the front lines. Between comedic club hijinks and genuine peril, the story captures the strange middle ground where middle schoolers become soldiers. The film focuses on how ordinary friendships bend under extraordinary pressure, and whether the connections forged in battle can survive the truth about what's really at stake.