The school mystery unfolds like a trap closing on its own trigger, every answer about what Kimberly really is just confirms how thoroughly these students are already caught. Oliver and Nanao feel like actual people learning to trust each other while the ground keeps shifting beneath them, not archetypes waiting for their character development moments. The show commits to making danger feel consequential without needing a body count to prove it.

Oliver Horn and Nanao Hibiya begin their first year at Kimberly Magic Academy. Oliver is a studious boy who handles both wand and blade with skill, while Nanao is a headstrong samurai girl from the faraway nation of Yamatsu, brought to the school after instructor Theodore McFarlane rescues her from a deadly battle. She becomes famous almost at once when she and four classmates save a student from a raging troll. Led by Oliver, who appears to be concealing a troubled past, the group of friends starts their magical training, and the two grow into both comrades and rivals. Kimberly hides dark secrets and constant danger, and only four in five students reach graduation intact. A near-fatal encounter in the labyrinth beneath the school soon shows the friends how deadly the academy can be, and they must stay together to survive and uncover its mysteries. The series is an action fantasy adapted from a light novel series.