Anywhere to get Japanese "Inaniwa Udon"?
While I haven't made it to this store yet , I imagine the new-ish TNT-Supermarket may be your best bet. It is in Thornhill and is part of a Supermarket chain that started in Vancouver.
I am planning a trip out there soon to check it out. I have heard amazing things.
Map to Thornhill location
Presumably you have tried and failed at Sanko on Queen W.
In any case you might want to give TNT a call before trekking all the way out there (assuming you are downtown).