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.

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.