Tokyo stocks closed 1.94 percent higher on Tuesday after the yen hit a fresh low in New York and following a long weekend in Japan, while investors await a G20 meeting later this week.
The benchmark Nikkei 225 index closed 215.96 points higher at 11,369.12, while the Topix index of all first-section shares climbed 1.16 percent, or 11.15 points, to 968.50.
The Japanese currency fell in New York trade, with the dollar buying 94.33 yen, compared with 92.70 yen on Friday. In Asia Tuesday the dollar was at 94.05 yen.
"(The dollar/yen) is back in the 94-yen levels," Yoshihiro Okumura, general manager of research at Chibagin Asset Management, told Dow Jones Newswires. "This is going to give a tailwind."
Despite the rise in the yen Tuesday analysts predict it will resume its downward trend after US Treasury official Lael Brainard backed Tokyo's economic policy, saying that "we support the efforts to reinvigorate growth and to end deflation in Japan."
The comment was essentially an endorsement of the recent yen weakening trend, traders said.
"Our only concern has been what the US would say about the recent yen moves. As that's all-clear now, the dollar will soon enter a new range of 95-100 yen," a trader in Tokyo told Dow Jones Newswires.
But investors are looking to a meeting of the Group of 20 economies later this week, which could have implications for the currency policies of major economies as Tokyo fends off claims it is manipulating the slide in the yen.
North Korea's nuclear test had little effect on the Tokyo market, as traders said the move has largely been factored in.
Softbank rose 4.72 percent to 3,545 yen after a report said US regulators had rejected a request to delay a review of the Japanese mobile firm's $20 billion takeover of Sprint Nextel.
Sony was up 1.17 percent to 1,381 yen, Toyota rose 0.51 percent to 4,920 yen while Canon added 2.16 percent to 3,305 yen.