Arcane refers to a human subrace that has undergone genetic mutation to develop the unique ability called etre. This power can bend the law of physics, which is why it is considered dangerous. Humans were so afraid that global war was started just to wipe them out.

Forty years later, there lives Theo, a young man who didn't give a hoot about being an arcane. All he wanted was to be a normal kid until a mad arsonist burned down his hometown. Fortunately, he and his younger sister survived, but it left them deep emotional scars.

Theo came to terms with his weakness, realizing he could not defend his younger sister in another crisis. He wanted to be stronger, so he enrolled in Leonia, a prestigious military-based academy in the nation's capital.

He had no idea that the threats terrorizing his country were nearly as severe as they were.