Rencke had a post in the European forum recently regarding surfing in native languages and the percentage was surprisingly high. Also, from my experience, people in Hong Kong and China tend to surf in Chinese more than English. The percentage is higher in mainland China than Hong Kong but it is still high.
For example, when I was in China last year, we went on a tour to South Korea, and looking up the tour agents on the net, most were in CHinese with only some in English.
(OT - the trip was vertsinly interesting, being an English speaker going to Korea with Chinese speaking guides - but that's another story....)
I would imagine the percentage in Japan is also very high, perhaps Bill con confirm thaqt for us.
So I would think the effeort and expense would be well worth it, particularly in the travel industry.
When you talk of "own domain and server" are you talking about a local country domain? If so that could be a challenge in some countries where a local presence would be required, China for example. Or are you thinking of additional dot coms?
BTW, written Chinese is the same world over, with a few slangish exceptions. It is only the spoken version that has dialects such as Cantonese, Mandarin, Shanghainese etc, so one translation will be anough.
Let us know how you go.