This book has lots of stuff to run a Crab campaign on the Wall or the Shadowlands or a ghostbuster/ cultist hunter campaign.
Overall, the schools presented here are really good additions with the caveats for the Kitsu Medic School that feels off for the Family and Clan, the Mirumoto Taoist Blade looks like the answer to the question "what happens when you mix a Mirumoto with a Togashi?" and the Kuni Warden because, just like with the Mirumoto Taoist, they are both Monk schools with access to kihō when right now there are like half a dozen kihō (or less) for each Ring, so these schools might become interesting later but right now, they don't have many techniques to choose from.
There are rules for creating Kakita Blades, but if you compare the rules presented here with the Kakita Blade example provided on the corebook, the one in the corebook is clearly a nemuranai and impossible to replicate with the rules provided here.
There is only one page of new "common" techniques but there's a ton of new Mahō. the rules for creating your own Oni look solid as well.