The Nikkei 225 index at the Tokyo Stock Exchange rose 56.10 points to 9,122.69, while the Topix index of all first-section shares rose 3.33 points, or 0.43 percent, to 780.44.
The rise came after US stocks racked up solid gains in a holiday-shortened trading session Tuesday, boosted by a strong factory orders report for May and robust June sales from leading US automakers.
The Dow Jones Industrial Average added 72.43 points (0.56 percent) to 12,943.82.
Heightened expectations for more policy easing measures from the European Central Bank, which will hold its monthly meeting on Thursday, also boosted investor sentiment, analysts said.
“The mood is slightly more ‘risk-on’ with the convergence of positive factors,” Hiroichi Nishi, general manager of equities at SMBC Nikko Securities, told Dow Jones Newswires.
The headline index looked bullish as it sat above its 25-day moving average, an indication of the current market’s strength, Nishi said.
Trading volume was likely to remain light ahead of the July 4th Independence Day holiday in the United States, analysts said.
Relative stability of the yen, which has steadily strengthened in recent months, also encouraged buying of Japanese shares, Nishi added.
The dollar stood at 79.84 yen in Tokyo, compared with 79.83 yen in New York Tuesday.
The euro was at $1.2602 and 100.64 yen, nearly flat from $1.2607 and 100.64 yen in New York.