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!

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.

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.

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.