Darkness, Aqua, and Megumin are back to continue their quest against the Devil King. Kazuma is back too, but the only adventures he has waiting for him exist within the criminal justice system.

A new discovery in a previously mapped out dungeon might be the first step toward Kazuma repaying his massive debt. Unfortunately for him, Aqua is determined to help.

As a result of a magic circle that Aqua had drawn in Keele's dungeon, strange explosive doll monsters have started to appear, putting the town at risk.

Kazuma is surprised to discover that Vanir had an extra life and has since quit his position as a commander to work at Wiz's shop, striking up a business partnership to sell products from Kazuma's world.

Vanir gives Kazuma the choice of either selling the intellectual rights for his real world products for a one-off payment of 300 million eris, or maintaining a profit-sharing contract of 1 million eris a month.

Kazuma's incorrigible ego forces him and his unmotivated idiosyncratic party to accept quest after dangerous quest following his bragging in front of his first hardcore fan. This time, the adventurer's guild requests that they take out a giant golem guarding ancient ruins...