From the back of the book:
The city of wizards and invading demons
- Labyrinth City
This book "Labyrinth City" is a sourcebook containing additional rules and data for "Night Wizard! The 2nd Edition". Besides special abilities already existing classes can get at high levels as new power for the wizards, it contains various new spells, magic items, weapons and pieces of armor.
The city of illusions awaits you
Labyrinth City
The ravine between dream and reality - the Kyoukai
The far side - the sealed away world of demons, and the front side - the front side - the reality protected by the world kekkai, between these two, another world exists. A world neither sealed away by the god nor protected by the world kekkai created by humans. The forgotten world the humans can't register, that is the world , the world in the ravine - called the "kyoukai". In this book we have prepared data like rules and data for adventuring in the Kyoukai, as well as sample boss characters or sample fortresses. By making use of that data, you should be able to prepare sessions more quickly.