Tokyo stocks opened 1.09 percent higher on Wednesday after the Dow Jones Industrial Average powered to an all-time high.
The Nikkei 225 index at the Tokyo Stock Exchange was up 127.61 points to 11,811.06 at the start.
Stocks were supported by a global commitment from central banks to take easing steps to support their economies, said Kenichi Hirano, market analyst at Tachibana Securities.
"Everyone's talking about the Dow's record high," he told Dow Jones Newswires. "The safety net has been built globally and there are ample funds floating."
The Dow reached its record high on Tuesday, exactly four years after hitting bottom in the worst economic crisis since the Great Depression.
After more than doubling its value in a steady march upward since March 2009, the Dow assaulted the record from the opening bell and ended the day at 14,253.77, nearly 90 points above the former closing high on October 9, 2007.
Shares in struggling Japanese electronics maker Sharp jumped 17 percent after media reports of a $108-million tie-up with South Korean giant Samsung.
The dollar was buying 93.31 yen in early Asian trade Wednesday, unchanged from New York Tuesday afternoon. The euro fetched 121.74 yen and $1.3044, also flat from US trade.