Rin Okumura, raised by Father Fujimoto, a famous exorcist, never knew his real father. One day, a defining argument with Father Fujimoto forces Rin to confront a terrible truth - the blood of the demon Satan flows in his veins! Rin vows to defeat Satan, but this means he must enter the secret True Cross Academy and become an exorcist himself. Can Rin fight demons and keep his demonic heritage a secret? It won’t be easy, especially when using his father's sword unleashes the demonic power within him!

While most students at True Cross Academy return home for summer break, Rin and his classmates are sent to a training camp in the wooded area, and the right to participate in a real mission will depend on their performance! Spotting and retrieving their targets in the woods is difficult and will require teamwork, skill, and a bit of magic - and Rin will have to learn to rely on his friends. But is Mephisto scheming something behind the scenes?