Kenshi Masaki is a 15-year-old boy that has unwillingly traveled from his home on Earth to the alternate world of Geminar. On Geminar, the countries wage wars using Sacred Mechanoids, humanoid exoskeletal weapons that were originally discovered within ancient ruins and developed over centuries. After being tricked by a mysterious organization into participating in an attempt to assassinate Lashara Earth XXVIII, the young ruler of the Shtrayu Empire, he ends up captured after he chooses not to kill her. Deducing enough about Kenshi to interest her and because his abilities make him an extremely valuable property, Lashara decides to take Kenshi under her protection.