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.

After returning from his trip to Arcanretia, Kazuma is living life without a care in the world, thanks to his debts being all paid off by the reward money he earned from eliminating one of the Devil King's generals, Hans. One day, a rookie adventurer named Ran comes up to him in the Guild Hall asking for a handshake. She's apparently become a fan of Kazuma after his consecutive defeat of the Devil King's generals! This puts him in an amazing mood, but it's not long before the Guild receptionist Luna appears, asking him to take on a quest to eliminate a golem. Wanting to look good in front of a fan, Kazuma ends up accepting, and heads towards ancient ruins with Aqua, Megumin, and Darkness in tow.