You can purchase Exclusive trainers in Japan. To be clear, you cannot buy these anywhere else in the entire world…. ok maybe on eBay if you’re lucky. If you’re going to Japan, why not take advantage of this. You can also take advantage of the tax free discount for tourists.
My favourite brand is Onitsuka Tiger, because of Kill Bill. On my last trip I purchased two gawg pairs and some socks too.
There are a few Onitsuka Tiger branches in Tokyo, and their flagship store. I must warn you, it is impressive and you will want to walk away with all of their trainers.
The staff in the shops do speak English. In each of the stores, I was provided great customer service.