Japan Open - Herrdubbel is a prestigious table tennis tournament held annually in Japan. It is one of the most important tournaments on the International Table Tennis Federation (ITTF) calendar and attracts some of the world's top players. The tournament is held in a single-elimination format, with the top two teams in each pool advancing to the main draw. The main draw is a 32-team knockout tournament, with the winner determined by the best-of-five-games format. The Japan Open - Herrdubbel has been held since 1984 and has been won by some of the greatest players in the sport, including Jan-Ove Waldner, Ma Long, and Zhang Jike.