The twelfth volume of the light novel comes with an unaired bonus episode. After defeating one of the Devil King's generals, Hans, and paying off his debts, Kazuma enjoys a worry-free life. Fresh from his trip to Arcanretia, he meets a fellow adventurer named Ran who compliments him on his defeats of the Devil King's generals. However, Luna, the Guild receptionist, interrupts his good mood by requesting Kazuma to eliminate a golem on a mission. To impress Ran, Kazuma accepts the quest and embarks on an adventure with Aqua, Megumin, and Darkness to ancient ruins.