This is a delightfully atmospheric little piece, set in the Tatakama World but with a portal to a shabby backstreet in modern Tokyo. The people and places are well-described and come to life well, a real feeling of an alternate reality that's out there somewhere.
The setting is a township, Niishima, and much of the main street and surroundings are described as well as the Niishima Inn itself. There's a lot going on, many stories being told and waiting to be told. Several key NPCs are given full stat block treatment, and there are four pre-generated characters (all native to the Tatakama world) that you can use. Other useful things include a Samurai template.
Now, whilst there is a lot going on, a lot to explore and discover here, there is no real 'adventure' as one might define it. Perhaps - especially if using the pre-generated characters - the aim is to find the portal. Or you may choose to turn things on their head and have modern characters find (or fall through!) the portal from modern Tokyo and attempt to survive in this strange world in which they find themselves. The Inn has a couple of haunts which may provide a challenge to those interested in finding out why they are there and how they can be laid to rest.
It's also worth a look if you are running or considering a 'fantasy Japan' setting using Dungeons & Dragons 3.X or the Pathfinder RPG.
Illustrations are beautiful, evocative, traditional Japanese in the main, it's a feast for the eyes as well as a good read!