Just like automobiles. Certain models are made specifically for overseas markets. If you search hard enough you might find a online retailer you can purchase them thru in Japan. Be sure they are a Certified Titleist dealer. Titleist does not ship outside Japan, so you cannot purchase thru them. There have been a few posts on here in the past with inquiries.

It's not just bags. The Titleist Japan market has always had unique bags, irons, balls, and other products not available in other parts of the world. I have never read anything official from Titleist as to why this was done that way and why it continues but it is what it is. To be fair, there are things available in the USA which sometimes are not released outside of here and Titleist USA only ships direct purchases to US addresses.

Some of the Asian items are very cool for sure!

tourspecgolf or ebay are your best bets!

Would love to have some of the gear USA and japen get here in Australia