Beautifully presented and with a wealth of detail this is much more than an adventure - it is a complete and detailed account of Naishou Province that provides scope for your own adventures, as well as containing plenty of material to get you started.
Starting with a map - beautiful brush-style - and a short piece of fiction, the Introduction explains what you have got hold of: basically a complete setting in which to run your adventures. Naishou Province is a single unaligned province of the Empire with plenty of scope for you and your players to stamp their own mark upon it. The history of the province is outlined - naturally it is right now a bit up in the air as it under temporary direct control of the Imperial family, but it has a long history rich in culture and strife. It is a prosperous area, somewhere - purposely not well-defined - outside areas under the direct control of the Great Clans and somewhat isolated by its geography, but its potential means that it has been squabbled over for generations.
After a brief word on a new fighting group - elite spearmen in the service of the Lion clan - and the characteristics of Naishou citizens, the next chapter is a detailed introduction to the main city of the province, Toshi no Naishou. It is the political and economic capital as well as the largest settlement by far, nestled beside a river. It is divided, in a somewhat haphazard manner, into different districts clustered around the Governor's palace. There's a samurai quarter, a merchant district and one for the heimin population - craftsmen, fisherfolk, farmers and the like. The eta live on the far side of the river in the main, an area regarded as inauspicious. Locals are surprisingly assiduous record-keepers and have a strong sense of their own history and ancestry. They are also very pious.
Important locations are listed, with stories and rumours to bring them to life. This portion reads like a good travel guide and quite makes you want to pay a visit. Then notable locals are listed, to serve as background figures or indeed to be woven into your stories. They include members of nearly all the Great Clans, jockeying for position. Fans of intrigue-based games should find plenty of interest here.
The next chapter looks at the settlements of Naishou Province. There are many fascinating towns and villages well worth a visit, often just for cultural delights even if the party's business does not take them there. For each there are notes on the appearance, culture, notables and whatever might be going on there... you will find plenty of material to help them spring into life. This section includes monasteries, ronin encampments and other locations as well as actual townships.
This is followed by a chapter on the geography of the Province. It's quite a diverse area and, as always, the landscape has shaped both peoples and events. The central fertile river valley is bounded by mountains on two sides, with a swamp to the northwest and forests to south and east. Several options are presented for what precisely is to be found in the forests, giving you plenty of leeway to set things up the way you wish. Within the valley, most travel is by river and there is a single main road. The swamp contains some ancient ruins, hinting at earlier inhabitation than even the citizens' meticulous records show. Finally, local wildlife is also discussed.
The final section, A Plague of Crimes, provides a starting adventure based around a cluster of ten small villages in the eastern part of the Province near a large and renowned monastery. There's been a bit of a crime wave, and the first couple of samurai who investigated met their deaths here. The default suggestion is that the Governor directs the party to take over the investigation, but you may have other ways of getting the characters involved, or may prefer one of the other suggestions given here. Once there, the party has a wealth of clues to investigate and many locations to visit as they do so. Discrete events are scattered throughout, but the investigation itself is quite freeform, allowing the characters to wander as they will, interacting with those that they meet. Once the characters find out what is behind the crimewave, they'll find others taking an interest in them and it all has the potential to turn quite nasty, whilst there are also options for you to force the action if they prove slow to grasp what is going on. A satisfactory brawl should result.
Pre-generated characters are provided for those who want to jump straight into the action. They are well detailed with plenty of background information as well as their stat blocks, but presentation is such that they will need to be transcribed onto character sheets - they're not laid out in such a way that you can hand out pages from this product to different players.
The whole thing is a delight to look at, with apposite and atmospheric art, as well as a joy to read, the places and people seeming to leap off the page into the alternate reality of your game world. Think I'll grab my swords and go visit!