Nikkei closed Wednesday to close above the 10,000 threshold for the first time since April 3 as investors are eager to see monetary easing under Japan's new Prime Minister Shinzo Abe.
The 225-issue Nikkei Stock Average finished up 237.39 points, or 2.39 percent, at the day's high of 10,160.40.
The broader Topix index of all First Section issues on the Tokyo Stock Exchange was up 22.49 points, or 2.75 percent, at 839. 34.
Gainers are insurers, steelmakers and paper makers, while the airline industry solo posted losses.
The turnover was about 2,088.8 billion yen (about 24.78 billion U.S. dollars).