Tokyo stocks jumped by more than four percent in early trade on Friday a day after the Bank of Japan unveiled fresh easing measures that sent the yen tumbling against the dollar.
The Nikkei 225 index at the Tokyo Stock Exchange was up 4.68 percent, or 591.08 points, to 13,225.62 several minutes after the opening.
The Bank of Japan (BoJ) embarked on a new era of huge spending Thursday by unleashing a flood of easy money in its boldest attempt to drag the economy out of a long spiral of deflation.
The yen slumped against the dollar and bond yields hit a record low after new governor Haruhiko Kuroda unveiled a doubling of the money supply and vowed no let-up in the battle against falling prices.
A weaker yen helps Japanese exporters by making their products more competitive overseas.
"The increased appeal of Japanese shares to potential overseas investors, combined with renewed weakening of the yen should lift the market still higher," SMBC Nikko Securities general manager of equities Hiroichi Nishi told Dow Jones Newswires.
The BoJ said it would expand its asset-purchase programme to include riskier bets such as exchange-traded funds (ETFs) and real-estate investment trusts. ETFs are similar to an index fund, but are market traded like stocks.
It will also buy longer-term government bonds, a move aimed at pushing down long-term interest rates to encourage companies and individuals to borrow instead of hoarding their cash.
The bank said it wanted to boost the monetary base -- the amount of currency in circulation including commercial bank deposits in BoJ reserves -- by 60-70 trillion yen ($630-$725 billion) annually to 270 trillion yen by the end of 2014.
The yen fell further in Tokyo morning trade, with the dollar soaring to 96.80 yen from 96.33 yen late Thursday in New York. The euro was at 125.16 yen from 124.60 yen.
In the United States, The Dow Jones Industrial Average rose 55.76 points (0.38 percent) to 14,606.11.