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.

A young girl had her voice magically taken away so that she would never hurt people with it, but her outlook changes when she encounters music and friendship.

A floating space without gravity where an infinite number of lights shine in different colors: The "Box of Wisdom." Inside of this box, there are multiple worlds, multiple timelines, and there used to be many different people. This is where Dual and Dorothy were fighting with enemies called "Viruses." Worlds infected by viruses must be erased. That is the duty, the job of these girls. However, one day, Dual and Dorothy feel the presence of a new Virus. Arriving at the scene, they see a girl being attacked by Viruses. After saving the girl, the duo wait for her to awaken so they can ask who she is, where she came from, and where she is going. Finally, when the girl opened her eyes, she gave her name, Rimo, and whispered only one sentence... "I must return to the flower patch..."