Asakura Rensuke, a Knight Candidate with a pristine facade, defends Japan against 'Radiant Beasts' alongside his unparalleled piloting skills of an Iron Steel Knight. Unexpectedly ambushed by a dark elf named Sheena, a reincarnated 'gyaru' high schooler from a different realm, Rensuke embraces her as family. Together, they dwell in an apartment and are swiftly entangled in a survival battle involving magical beings reborn from diverse worlds. Witness the saga of two outsiders in a mythical apocalypse.