Aisaka Koyomi and Shizuha Sizumu had been friends since kindergarten. They both were accepted in their dream school "Grover's academy" after all their hard work and had hoped to have a pleasant High school experience but reality is often disappointing. When they heard a loud blast from the center of the city followed by several clashes it filled them with horror.

The chain of calamities follow as if some great foreign power was starting to take control of humans.