Leaders of the Mekong river region (2nd L- 2nd R) Cambodian Prime Minister Hun Sen, Laotian Prime Minister Bouasone Bouphavanh, Myanmar Prime Minister Thein Sein, Thai Prime Minister Abhisit Vejjajiva and Vietnamese Prime Minister Nguyen Tan Dung are greeted by Japanese business group leaders Fujio Mitarai (R) of Keidanren and Tadashi Okamura of Japan Chamber of Commerce for their luncheon in Tokyo on November 6, 2009. The leaders are here to attend the first Japan-Mekong summit meeting.