The use of white models is the Japanese's idea of making their brands look more serious, and international/western in the business. Sorta like how people there use to think "Made in France" was the epitome of garment production.
My hairdresser wears head to toe Rick Owens, and I'm not even talking about that basic shit like the t-shirts and leathers, he wearing that off the runway stuff you expect to see a boutique like LN-CC to carry.
Daaaaaamn, I just had the best customer service chat with an online retailer. A JAPANESE online retailer. That is not something I expect being a westerner. These guys measured the item I wanted on the spot, WITH photos.