Tokyo stocks ended up 0.81 percent Thursday, with the Nikkei 225 index hitting a seven-month high on optimism over the US economy and speculation of more Bank of Japan monetary easing.
The benchmark Nikkei added 76.32 points to 9,545.16, its highest close since late April, while the broader Topix index of all first-section shares gained 0.88 percent, or 6.88 points, to 788.74.
Boosting sentiment in Tokyo was a rise in the Institute for Supply Management's November index on activity in the vast US service sector.
Markets have also been speculating over further Bank of Japan policy measures as Shinzo Abe, head of the main opposition Liberal Democratic Party (LDP), vowed to pressure it to launch more aggressive easing measures if he wins a December 16 general election.
"With the prospect of the LDP's return to power looming, there is hope in the market that foreign investors will step up Japanese stock buying," said Hiroichi Nishi, assistant general manager of equity research at SMBC Nikko Securities.
In currency trading, the dollar edged higher against the yen, changing hands at 82.48 yen from 82.42 in New York on Wednesday afternoon.
The euro bought $1.3055 and 107.69 yen, compared with $1.3064 and 107.71 yen.
The weakening yen helped exporters' shares, with Canon up 2.59 percent at 3,000 yen, Honda climbing 1.55 percent to 2,747 yen and Sony adding 3.42 percent to 816 yen.
Optimism over China's economy helped China-linked shares, with factory automation equipment maker Fanuc up 1.71 percent at 14,230 yen while construction machinery giant Komatsu rose 1.29 percent to 1,880 yen.
Japanese electronics giant Sharp surged 9.94 percent to 199 yen in the wake of news it struck a capital injection deal with US-based chipmaker Qualcomm.
The cash-strapped Japanese firm's shares also benefited from Taiwan's Hon Hai Precision saying a stalled deal to invest in Sharp was still on the table.
-- Dow Jones Newswires contributed to this article --