I doubt it. These replacement blades in japan cost almost nothing comparatively.
Note that this is a japanese site, seller in japan, $12.30 from what I can tell for a "buyout price" (fixed price listing) and the well-appreciated Z kataba.
https://buyee.jp/item/yahoo/auction/o377204954
Some of the replacement blades by themselves are about $25 for a pack of 5 (smaller ones less).
My advice is to stick with a seller with a japanese origin (where it's shipped from) if you'd like japanese product for certain, but I'm guessing what he's saying is that the cheaper (different brand) of "japanese saws" sold at retail home centers are sometimes chinese made. Not "Z saws" sold in the UK by retailers are fakes - I haven't seen it.
We get shelled on stuff like this that goes through distribution and retail markup to be sold in the western world, though. Buying from japan can be cumbersome, too, as while this saw is $12.30, you can expect a service like buyee to charge about $5 shipping for each item and then a $15 consolidation fee plus shipping. If you wish to make a large order and surface ship it, you could get a lifetime supply of pull saws and spare blades for about half or so of what they cost here in the states.
Sellers on japan using ebay are either doing the manual work themselves to sell you a $30 saw and hopefully make about $10 on the transaction, or they're using something like amazon japan to drop ship them. Relisting of stuff in japan is common - it's legit goods. when you see it, you know the goods in country are much less expensive than we think they are.
When you see Z saws or Gibson USA pickups originating from china, then i'd be suspicious.
