There is two main Japanese rifle variants that are kicking around (excluding carbines, Type 30s, etc.). The Type 38 and Type 99. Type 38 is the older of the two and uses the 6.5x50sr cartridge. The Type 99 is the newer of the two adopted in 38 or 39 and uses the 7.7x58 cartridge.
Things to look for on the Type 38s are condition, bore condition, and matching numbers (be careful some have assembly numbers which aren't the same as serial numbers so just because the serial number on the receiver is different from the bolt doesn't necessarily mean it is mismatched). Later Type 38s have a aperture sight for the rear sight as opposed to a 'V' notch (both are located at the same spot on the barrel). Many Type 38s are extremely rough, with bores that are basically destroyed. These rifles had a long rough service life. Most in Canada are in rough shape and generally lack all these things that you want to look for. Also the dust cover is something to look for as well, however you want one that is matching to the rifle or assembly number.
For the Type 99 the things to look for are matching numbers, condition, and bore condition. Generally speaking the Type 99s are in better shape than the Type 38s, much shorter service life plus they had chromelined barrels for most of production which really prevented most the bore condition issues (I personally have never seen a Type 99 with a terrible bore). There is three major Type 99 variants you will find, early which has a monopod and anti-aircraft sights, mid which will lack the monopod and anti-aircraft sights (note depending on the series and manufacturer will determine what features should be on the rifle), and late which is really crude and rough (comparable to Last Ditch K98k).
There is other variants, but these are the ones your most likely to run into. They aren't very common in Canada and most are rough that you do find. Many people have had a upswing in Japanese firearms and the supply is really outstripped by demand. If you want a great example importing might be your only option. Also a good reference book 'Military rifles of Japan by Fred L Honeycutt'. It has many pictures and descriptions as to how the rifle should look based on series and features.