The Nikkei 225 index at the Tokyo Stock Exchange, which was closed for a national holiday on Wednesday, rose 289.65 points to 17,942.33 by the break, while the Topix index of all first-section shares climbed 1.50 percent, or 21.47 points, to 1,449.19.
Major exporters including Toyota and Sony got a boost from the weaker yen, which inflates their profitability.
The dollar bought 120.29 yen, slightly down from 120.35 yen in US trade Wednesday but sharply up from 118.50 yen in Tokyo Tuesday.
“If the yen continues at these levels, it’ll be positive for Japanese stocks,” said Mitsushige Akino, an executive officer at Ichiyoshi Asset Management.
But if talks on Greece’s debt “break down there are risks that it’ll cause the currency markets and risk assets to move”.
A meeting between Greece and its European creditors on restructuring the country’s bailout ended without agreement late Wednesday, and talks are now set to go down to the wire next week.
Greece’s bailout is due to expire at the end of February and failure to agree on an extension would see Athens default on its giant debt, likely leading to its exit from the eurozone.
Prime Minister Alexis Tsipras led the hard-left Syriza party to victory in elections last month vowing to bring an end to austerity measures imposed under the bailout.
In Japan, fresh data showed that December machinery orders — a key leading indicator or capital spending — jumped 8.3 percent on-month, offering some hope for Prime Minister Shinzo Abe’s programme to kickstart growth, dubbed Abenomics.
“The machinery orders numbers were extremely good,” Andrew Clarke, director of trading at Mirabaud Securities Asia, told Bloomberg News.
“It reflects a weaker yen and I would say it underlines the fact that Abenomics is working, despite its critics.”
In Tokyo share trading, Toyota was up 1.82 percent at 7,853.0 yen while Sony jumped 3.95 percent to 3,195.0 yen after news that it reached a deal with Walt Disney to make a new Spiderman movie.
Fanuc was up 3.76 percent at 21,535.0 yen by the break after hitting a record high of 21,540.0 yen in early trading following news that a US hedge fund led by billionaire Daniel Loeb has taken an equity stake in the Japanese robotics giant.
Loeb’s Third Point is well known for pressuring firms to boost their profitability, including pushing Sony to spin off part of its entertainment business. The electronics company resisted those calls and Third Point later sold its stake. (AFP)