The benchmark Nikkei index at the Tokyo Stock Exchange rose 157.90 points to 9,849.74. The Topix index of all first section shares added 1.43 percent or 11.98 points to 851.85.
The Tokyo market will be closed on Friday to kick off the annual Golden Week holidays.
The bourse will open only on Monday and Friday next week.
Official data released before the opening showed industrial output and household spending last month suffered record falls in the aftermath of the March 11 disaster, which damaged supply chains and consumer sentiment.
But investors paid more heed to US Federal Reserve chairman Ben Bernanke's comment that the central bank had no timetable for ending its low-interest rate policies.
Brokers believe the March industrial outcome was partially offset by a brighter outlook for April and May, said Hideyuki Ishiguro, a strategist at Okasan Securities.
Relatively strong corporate earnings despite the earthquake and tsunami also helped brighten sentiment, they said.
"The market seems to be reacting more favourably to earnings than we had anticipated," Cosmo Securities equity strategist Toshikazu Horiuchi told Dow Jones Newswires.
"Expectations are growing that Japan will display its underlying strength through speedy recovery efforts," Horiuchi said.
Sony plunged 4.48 percent to 2,260 on news Wednesday that its online video game network had been hacked.
Kyocera rose 5.33 percent to 8,890 after it said its net profit surged by nearly a third in the January-March quarter, supported by robust sales of communications equipment.
The dollar sagged to 81.71 yen from 82.15 in New York Wednesday following the Fed's decision to hold its key interest rate at 0-0.25 percent "for an extended period."
In New York on Wednesday the tech-rich Nasdaq Composite index hit its highest level in more than 10 years as US stocks pushed upward after the Fed rate decision.
Riding news that the central bank would not raise ultra-low interest rates, the Dow Jones Industrial Average also surged, adding 95.59 points or 0.76 percent to finish at 12,690.96, a three-year high.