You are correct it is a fake. They never put Kanji (japanese writting) on the blade. On the tang yes, but never on the blades. Carvings Yes. Better pic's would be great to point other things out. But that collar Habaki is poorly done. The blades tip(Kissaki) is not defined and the steel on the blade looks more like Damascus than the fine grain(hada) it should have. I would put this in the Chinese copy category.
I'm just at a novice level(20+ Years) for these so Please wait for those that have studied these for many more years than I. They will be along very soon.
As to what makes it a fake ... well, every part is similar, but not the same, as those on real swords. Look at and compare the details of that sword with those of this one ...
Of course the blades are vastly different because the linked sword is a Yasukunito but scroll down and look at the mounts etc. and you will see the difference in the quality of workmanship.
Was I close Stu? Was I looking for the right things? Go ahead and hit me. I am still learning and I can take it. It is the faults that make us stronger and then know what we must improve upon.
I agree that this is a fake for the afore mentioned reasons. I would like to respectfully make one correction to this thread. Kanji can at times be found carved in to the surface of the cutting edge part of the blade. The carvings usually have a rekigious overtone. It is more common to find bonji, a sandscript religious character carved in to a blade.
LIFE'S LOSERS NEVER LEARN FROM THE ERROR OF THEIR WAYS.
FYI re kanji; just in case you were wondering what it said:
That is of course correct. I've seen photos of some with kanji on the blade. One was a Gensuito if I remember correctly. I think it's safe to say though that they are done with a great deal of skill as opposed to what we see in the sword posted by Bluescan. Would you agree? It is the large clumsy type shown here that I made reference to that my red flag comment.
Wow! Thank you all for the great answers and thank you for the links, i really appreciate it. Looking forward to learn more about japanese swords.