each country is a cost center. so, for small quantities, they should have no problem to help each other out. when you have a big difference in pricing for nearby countries, then they will have a problem. Imagine, if HK so much cheaper than Japan, Japanese consumers (and also some small retailers) will stock from HK but when the lenses have problems, they go to the Japan Service Center to get it fixed or replaced. How would the balance sheet for the Japan Service Center looks when they have more lenses fixed than sold from their Japan outlet?
Thus, it is always in the best interest of the company to ensure that pricing difference between countries are kept to a minimum in non--perishable categories (McD is different, you can't buy McD in HK and then consume or resell in Tokyo

).