Tokyo stocks opened 1.30 percent higher on Monday as the yen weakened further against other major currencies.
The benchmark Nikkei 225 index at the Tokyo Stock Exchange was up 117.11 points at 9,141.27 at the start.
"After Friday's rise, there is renewed energy in the market," said Hiroichi Nishi, general manager of equities at SMBC Nikko Securities.
"With the weaker yen and stronger US stocks, the market is looking more bullish," he told Dow Jones Newswires.
The Nikkei rose 1.90 percent Thursday and another 2.20 percent on Friday, driven by a weaker yen after the frontrunner to become Japan's next prime minister called for "unlimited" monetary easing by the central bank.
The euro bought $1.2758 and 103.88 yen in early Asian trade, up from $1.2741 and 103.60 yen in New York late Friday. The dollar rose to 81.43 yen from 81.31 yen.
US stocks snapped a three-day losing streak Friday after political leaders signalled a determination to compromise to avoid sending the economy over the "fiscal cliff".
As the White House opened talks with congressional leaders on closing the deficit and averting the harsh tax hikes and spending cuts slated for January 1, the Dow Jones Industrial Average ended up 0.37 percent at 12,588.31.