Where Can You Get Condoms To Buy That Will Fit Westerners

You can try one of the Don Quijote stores. Plenty in the Tokyo area.

From previous threads look for Big Boy Large with a horse on the label or perhaps Sagami Original L-Size.

I think Big Boy make one size larger too for those who need it...

Don Quijote
Personally, I prefer the elephants.....

Impressive! I found the elephant too big for me, so I'll stick with the horse from now on. But whatever you choose, don´t rely on the Japanese love hotel condoms, they are what? Chihuahua size?
Try Condom Mania in Harajuku. in Tokyo.
If you know exactly what you want Condomania is fine, but the products are not well described and the staff are minimum wage bored no nothings.
Here is a site if you have a mailing address or can be delivered via Black Cat (Yamato). Use Google Chrome that translate sites. Shipping is in a plain brown box with no indication of adult contents.

The Big Boy brand is excellent (though expensive, like all condoms in Japan). Horse or Elephant size (just going by packaging, I can't remember the sizes) will easily fit a standard+ western cock. I am roughly 6~6.5" and not at all a girth-monster. Their largest and second largest sizes fit very well (a sad testament to the local mean).

Also, little to no smell on Big Boy brand, which is a huge plus to those of us with a Pavlovian aversion to that noxious spermicide/lubricant/latex odor. Worth the extra cost if that bothers you about rubbers.
Btw, if you are nervous about getting BBBJ at a particularly skeezy place, showing up with a Big Boy skin in-pocket is a plus for the girl due to the taste/ordor issue. I don't care how cheap it is: nobody wants to go down on a stinky bone. You'll be remembered for your consideration if nothing else. :)