Chris tells Kazuma that the necklace he and Iris swapped bodies with is a sacred treasure, and it is dangerous and can threaten lives depending on its use. Princess Iris is in danger! Two robbers dressed in black sneak into the royal castle at night!

The Devil King's army attack alarm rings in the royal capital! The adventurer's guild calls on high-level adventurers to join the battle. Having failed to capture the thief at Alderp's mansion, Kazuma joins the fight in order to redeem his reputation.

Kazuma has crashed Darkness's wedding to Aldarp and pays him the two billion eris he says he's owed. Aqua and Kazuma try to make off with Darkness but Aldarp won't relinquish her so easily and orders his guards to stop their escape.

Kazuma and the gang fail to defeat the hydra in the lake near Axel. The gang hopes to rely on knights from the capital, but they've been delayed due to a bandit disturbance for which a bounty has been issued. Darkness, however, is obsessed with the hydra.

Darkness's wedding to Aldarp is imminent. Despite Aqua's and Megumin's pleas, Kazuma has no intention of intervening. Vanir then visits the mansion and reveals a shocking secret to Kazuma.

Kazuma and the gang receive a letter from Princess Iris. She wants to share a meal with them while hearing about their adventures. While Kazuma is giddy with wonderment of her beauty, Darkness is terrified of heads rolling in the event of any rudeness.

What started as dinner at Darkness's mansion with Princess Iris has turned into Kazuma being dragged back to the castle! Rain explains the situation, and Kazuma agrees to keep Iris company. His wild stories leave the princess with stars in her eyes.

Kazuma thinks of a way to stay in the capital for Iris's sake, and declares that he will capture the thief who's causing a stir in the streets! Since the thief targets nobles with bad behavior, Kazuma and his friends decide to stay at Alderp's mansion.

Kazuma and his friends return to Axel and receive 300 million eris as a reward for subjugating Sylvia, an executive of the Devil King's army. Kazuma and Aqua go to high-end restaurants, and Aqua enjoys her long-awaited life as a celebrity.

Darkness departs the mansion leaving behind a note. Not satisfied by a single note, Kazuma, Aqua, and Megumin protest in front of the Dustiness manor but are rudely turned away. Kazuma, frustrated with everything, is approached by Dust who needs his help.

After defeating Sylvia at the Crimson Demon Village, Kazuma and his party look forward to receiving a reward that could mean freedom from the grind of having to fulfill quests. Kazuma himself, however, seems to be having nightmares and bouts of paranoia.