As the offspring of an Angel and Valkyrie, (Y/N) (L/N) is already a powerful being. However, he is also the wielder of the Sacred Gear "Warrior Spirit", which contains Ancalagon, the third heavenly dragon. He has traveled the world and fought countless foes, but now he is being told to attend school and take a break from fighting. At Kuoh Academy, however, he meets some intresting individuals that may make his life even more interesting than it was before.