When Nazarick was invaded by Chaos Beasts, some sort of phenomena proceeded to alter not just the minds of the NPCs, but also the internal layout of Nazarick into a place of New Year festivity and atmosphere.
Mass for the Dead Arc
- Main article: Mass for the Dead Arc
Momonga having stepped out to the 1st Floor of Nazarick to receive Solution Epsilon and the protagonist finds a Hatsumōde that leads to a changed Nazarick. Instead of being taken to the 4th Floor, the group finds themselves in a desolate desert. There they greet various characters that have been affected by the New Year phenomena.
Coming across the shrine where Cocytus and Narberal Gamma they are barred from going any further unless they battle. The group defeats the two and are allowed to pass where they meet with Yuri Alpha and Lupusregina Beta. When Yuri is asked why she left her post, Yuri replies that it was a holiday. All in all Yuri and Lupusregina appear to be mildly affected by the New Year atmosphere. Though they invite him to write poetry though they are suddenly attacked by Chaos Beasts. After dispatching the monsters the group continue to participate in the festivities before heading through the Gate to the 10th Floor. After the Ruler of New Year was defeated, Nazarick had been restored to as it was.
The temple was created when the layout of all the floors below the 1st Floor in Nazarick were merged and changed by the Ruler of New Year. The dungeon was converted into a realm with a hazy sky, misty fog, and desolate sands. The Takemikazuchi Shrine was the only structure that existed in the desert dimension. The Gate that was normally used to transport to other Floors was located in the shrine and led directly to the Throne Room where Shiramochi-ō waited. The roof of the shrine possessed an ornament that was similar to Warrior Takemikazuchi's horns.
Hatsumōde: A Japanese stone tori located on the 1st Floor of the Great Tomb of Nazarick. It is decorated with a gold dharma wheel at the top, with lengths of shimenawa wrapped on either supporting pillars. In the middle of the tori is an amethyst dimensional gateway which serves as an entrance to the converted Nazarick.
- The location seemed to be based on Kashima Shrine, where the shrine is dedicated to Takemikazuchi-no-Ōkami, patron Japanese deity of martial arts. In addition, the shrine is said to be a pilgrimage location for thousands during the New Year celebration.