Tokyo stocks rose 1.04 percent in early afternoon trade Thursday, after the Bank of Japan stuck to its view that the economy was picking up moderately and held off further easing measures.
As afternoon trading started, the bank also announced it would leave interest rates unchanged at between zero and 0.1 percent while holding steady on a 70-trillion-yen ($891-billion) asset purchase programme, its key policy tool.
The benchmark Nikkei 225 index at the Tokyo Stock Exchange was up 1.04 percent or 92.57 points at 8,973.73, while the broader Topix index of all first-section shares gained 0.59 percent, or 4.52 points, to 750.22.
Markets were also looking to an unfolding political drama in Japan over a plan to double the nation's consumption tax after opposition lawmakers threatened to block its passage in the upper house of parliament.
The government has said the plan to raise sales taxes to 10 percent by 2015 was crucial to chopping Japan's massive public debt.
Sony rose 1.86 percent to 929 yen and Toyota was up 0.79 percent at 3,185 yen.
Nikon shares tumbled 7.18 percent to 2,107 yen after the camera maker cut its operating profit forecast for the fiscal year through March 2013.
On currency markets, the euro bought $1.2381 and 97.05 yen, compared with $1.2363 and 96.99 yen in New York late Wednesday.
The dollar was quoted at 78.38 yen against against 78.45 yen.
In the US, the blue-chip Dow Jones Industrial Average closed at 13,175.64, a gain of 7.04 points, or 0.05 percent, on Wednesday.