Tokyo shares opened up 1.56 percent on Monday as the yen weakened following G20 talks that averted any criticism of Japan over the unit's recent slide, which has stoked fears of a currency war.
The benchmark Nikkei 225 index gained 174.66 points to 11,348.49 in the first minutes of trading.
In foreign exchange trade the dollar strengthened to 93.81 yen, from 93.53 yen in New York on Friday, while the euro bought 125.26 yen from 124.97 yen.
Bargain hunters also moved in after the headline index dropped 1.18 percent on Friday as fears grew that the G20 meeting in Moscow would see Japan accused of manipulating its currency to boost its exports.
A communique from the meeting refrained from singling out Japan despite heavy criticism, particularly in Europe, over the new government's loose monetary policy, which some have charged is being used to weaken the yen.
The new government of Shinzo Abe, as well as the central bank, have repeatedly denied the claims.
"We will refrain from competitive devaluation," the statement said, adding that we "will not target our exchange rates for competitive purposes".
The Nikkei index was tipped to rise on the softer-than-feared tone of the statement, said Yoshihiro Okumura, general manager of research at Chibagin Asset Management.
"Japan wasn't mentioned by others," he told Dow Jones Newswires. "The results were largely positive for Japan."
Wall Street put in a mixed session Friday, with the Dow Jones Industrial Average inched 0.06 percent higher at 13,981.76, while the broad-based S&P 500 was down 0.10 percent.