Since ancient times, the human world and the Beast Realm have been engaged in a protracted war for the sake of land acquisition. After millennia of conflict, with the Beast Realm steadily retreating, the war finally came to an end a thousand years ago, with both sides agreeing to a truce. The Beasts were allowed to retain their lands, but on the condition that every Beast must obey humans and be summoned at any time and place to assist them.Since then, a new profession emerged in the human world - the Summoner.All humans were eligible to become Summoners, and this profession quickly flourished in the human world—Today, we are going to tell the story of a Summoner... Oh, no, a Summoned Beast.