The anime takes place in a world that long ago featured the existence of magic, but has long since lost that ability. The story begins when the very normal high school student Mangetsu Kohinata meets Shingetsu Ernesta Fukami, who has migrated back to Japan from Germany, on a night with a full moon.

In the city of Orario, beneath an impossibly tall tower, lies the dungeon. Only adventurers who form partnerships with the gods themselves have any hope of defeating the monsters that lie within. But the dungeon is not the only place where monsters exist. Far from Orario, in the ruins of an ancient city, a new threat arises. To counter this threat, the goddess Artemis has come to Orario in search of a champion-but it’s not Ais Wallenstein (the legendary Sword Princess) nor Ottar (the strongest warrior to ever enter the dungeon) that she chooses. Rather it is Bell Cranel, a newbie adventurer partnered with a low-tier goddess.

Monster Strike: The Movie serves as a prequel to the net anime series based on the game of the same name. The anime tells the story of Ren, who returns to his hometown with no memories of having lived there. When a a cell phone repairman installs the Monster Strike app on his phone, Ren finds himself pulled into a real-world version of the game and begins piecing his memories together again.