Summary: When an unknown gate to a different world suddenly opens one day. Monsters called Aragami appear and start attacking humanity. However, some humans develop superhuman like power that can defeat the Aragami. But these lead megacorporations are known as the North Star Foundations to pass the act called the Striker Act and created The Striker System. In 2721, in Skystar City, a girl named Rui Kamiya whose a Striker in training who wants to be a strong Striker like her older sister so she heads to Skyline Academy.