18 years ago, a powerful monument was discovered on a mysterious island. The monument contained data only certain people could extract who became students of the island's school. By being able to extract the data, the students are able to summon a creature that they fight with. Of these people, Satou Taketora is your typical lazy kid who doesn't do anything, hence he's ranked dead last. But one day, he's dragged into a battle with his old childhood friend, but to everyone's surprise his summon is more than meets the eye
