Reddit reviews Tobidase Doubutsu no mori (Animal Crossing : New Leaf) Super Complete Catalog Nintendo 3DS Game Guide Book [Japanese Edition]

Amazon! The people in that thread recommended this one, this one, and finally this one! Even if you can't read Japanese, the pictures give you a lot of really helpful information. The last one I linked even has the image of every single villager's starting home set-up (at the time of its publication, anyway). And if you want to get an idea of exactly how much information they have...well, here's a comparison of the thickness of the Prima guide and the Kanpeki Japanese guide.

There are a lot of them out there, but you might find some pics of their contents on Google images or tumblr if
you take a look. (The links to tumblr images in that thread died.) Good luck and happy hunting!

Famitsu (the publisher of this guide) made a pretty good one known as the perfect guide. I'm currently using this and absolutely love it. It's well balanced with a lot of info and pictures that are big enough to see the details.

Another good one is from Nintendo dreams that is more structured like a catalogue and also named as such. If you enjoy keeping track of your catalogue progress and/or are a completionist this might be up your alley.

There are a couple of others but I think these two are the most used. And regarding the Japanese, if you know the basics you'll be fine. Even those who don't speak/read the language can use these books because most of it is pretty self explanatory.