Born as the sole being with a holy power, the "Saintess" Akurei—or Akira, as he’s known—is raised as a boy by his parents, who fear that the Saintess could once again spark conflict, just like in past wars. Now 18, Akira is set to study abroad in a neighboring country, hoping for a peaceful, uneventful school life. However, just as he starts settling in, he unexpectedly catches the attention of not one, but three captains of the Holy Knights, all insisting, "We want you to join our order!"