I believe the most important Asia Markets is Shanghai Composite (China), next is Nikkei (Japan), than Hang Seng (Hong Kong).
It's the eurostoxx indexes against which many more portfolios are benchmarked in Europe than dax. In Asia its not relevant to determine a major index because the markets there are so fragmented. If you must, build a composite made of Hsi, China 50, kospi, asx, and Nikkei.
KOSPI index has the highest option volume, and quite large stock trading volume as well: http://www.businesskorea.co.kr/news/articleView.html?idxno=53731
Well it used to be the Nikkei index first and then the Hang Seng. Now I guess China has overtaken both of these economies.