Watch Is It Wrong to Try to Pick Up Girls in a Dungeon? III OVA Online

On their way back from the 18th floor, Hestia, Bell, and the others accidentally uncover a hidden, mystical hot spring, and they decide to stop by to refresh themselves until creatures lurking in the dark appear to attack them.

Continuing his adventure to get stronger in order to traverse deeper into the "Dungeon," Bell Cranel wanders the Orario city streets with his friends and the goddess Hestia. That evening, the city is filled with stalls and games as it celebrates the Holy Moon Festival.Hermes, a god, hosts one such activity where participants are asked to pull a spear embedded in a crystal boulder; those who succeed will receive a special gift: a trip around the world and a divine blessing from the gods! Bell and his merry group challenge one another to claim the prize. But behind the facade of an innocent party game lies a preface for a daring quest ahead.

Goddess Festival—A fruit festival that brings the labyrinth city of Orario to life. Goddesses symbolizing fertility are enshrined on the altar, and among them is the Goddess of Beauty. Bell Cranel, who has survived and returned to his daily life from the dead depths of the dungeon, is here and ready to enjoy the bustle of the Goddess Festival until he receives a letter from a girl at a small bar in a corner of Orario—"To Mr. Bell, please go on a date with just the two of us at the upcoming Goddess Festival. From Syr." Syr's single-minded determination will drive both Bell and the labyrinth city crazy. Meanwhile, the Einherjar, the warriors who claim to be the "strongest," are now suddenly on the move...

Special recapping all three previous seasons of DanMachi with Bell Cranel and Hestia's VAs' commentary.

Second part of Dungeon ni Deai wo Motomeru no wa Machigatteiru Darou ka IV.