Tokyo stocks opened 1.23 percent higher on Wednesday following sharp rises on US and European markets backed by higher oil prices and greater optimism over a deal to renegotiate Greece's debt.
The Nikkei 225 index at the Tokyo Stock Exchange rallied 213.45 points to 17,549.30 at the start.
The Dow Jones Industrial Average jumped 1.76 percent on Tuesday as US oil prices surged seven percent to the highest level of the year.
The higher oil prices eased market fears that the steep drop in the commodity signals major global economic problems.
European equities and the euro jumped on hopes of a resolution in Greece's debt talks.
Greek officials are pushing the idea of debt swaps that would avoid the need for creditors to accept 'haircuts' on the country's 315-billion-euro ($361-billion) foreign debt.
The euro was firm early Wednesday, buying $1.1456 and 134.81 yen, slightly lower than $1.1479 and 134.96 yen in New York Tuesday afternoon but sharply up from the levels of $1.13 and 132 yen seen in Tokyo on Tuesday.
The dollar was at 117.65 yen early Wednesday compared with 117.57 yen in US trade.