International arrivals were up 12% to 526 million in the first eight months of 2004.
The report predicted growth for the remainder of the year and a 4-5% increase in 2005.
Asia and the Pacific showed the greatest upturn with a 37% improvement in tourist numbers for 2004.
Director of the Japan Convention Bureau Simon Halewood said: "From 2002 onwards, we have noticed a favourable trend in business tourism. Japan is picking up more international meetings business." Globally there was mixed news for business travel, which underperformed compared to leisure in Europe, the US and the Asia Pacific.
However, 34% of business travellers said they would spend more in the next 12 months.