Tokyo stocks jumped 0.77 percent on Friday to closed at a three-month high after gains on Wall Street that were driven by fresh support for the euro from Germany and upbeat US data.
The benchmark Nikkei 225 index at the Tokyo Stock Exchange added 69.74 points to 9,162.50, its highest close since May 8, as a weakening yen also fed buying appetite.
The broader Topix index of all first-section issues rose 0.88 percent, or 6.69 points, to 765.81.
Sentiment was buoyed by German Chancellor Angela Merkel who on Thursday gave solid backing to European Central Bank chief Mario Draghi's recent vow to do everything possible to defend the single currency.
Her comments helped lift Wall Street on Thursday, with the blue-chip Dow Jones Industrial Average finishing 0.65 percent higher at 13,250.11.
A weaker yen in Friday trade also helped shares of Japanese exporters, who suffer when the currency is strong by making their products pricier overseas.
The dollar crept above 79.40 yen in afternoon trade with some dealers eyeing the greenback to test 80 yen.
"While the stock market has been creeping higher as US interest rates have picked up, a firm grasp on the 80 mark for dollar-yen is key for a viable Nikkei rally," Investrust CEO Hiroyuki Fukunaga told Dow Jones Newswires.
CLSA equity strategist Nicholas Smith said: "Global markets had been so risk-off for the last few months that it's about time they went risk-on again."
Nomura analyst Shoichiro Yamauchi said the bullish sentiment could push the Nikkei beyond 9,500 in the near-term.
Sharp reversed early losses to rise 5.14 percent to 184 yen following a Nikkei business daily report that Taiwan's Hon Hai Precision wanted to double its stake in the troubled Japanese electronics giant to 20 percent.
Other reports said Sharp was eyeing selling off its main operations to repair its dented balance sheet.
Automaker Toyota rose 0.77 percent to 3,275 yen, banking giant Mitsubishi UFJ Financial Group rose 2.21 percent to 370 yen, and Hitachi jumped 1.92 percent to 478 yen.
Honda Motor gained 2.44 percent to 2,642 yen after the Nikkei said it would hike its scooter production in the key Indonesian market.
Mobile phone operator Softbank fell 2.64 percent to 3,135 yen, while Japan Tobacco lost 3.65 percent to 2,480 yen.