Tokyo's benchmark Nikkei index surged more than 2.3 percent Thursday on US rallies and a cheaper yen against the dollar as fears of an all-out Middle East conflict receded.
The Nikkei 225 index, which dropped 1.57 percent on Wednesday, rose 2.31 percent, or 535.11 points, to close at 23,739.87. The broader Topix index gained 1.63 percent, or 27.65 points, to 1,729.05.
Japanese shares were being supported by "rallies in US shares, and the yen's depreciation against the dollar" after the safe-haven currency strengthened on tension between the US and Iran, said Yoshihiro Ito, chief strategist at Okasan Online Securities, in a commentary.
The dollar fetched 109.22 yen in Asian afternoon trade, against 109.13 yen in New York and 108.43 yen in Tokyo on Wednesday.
"Trading has been volatile since the beginning of this year due to the Iran situations," said Daiwa Securities chief technical analyst Eiji Kinouchi.
"But trading is likely to stay calm from now on as the market is shifting its focus from geopolitical factors to the real economy," Kinouchi told AFP.
Among major shares in Tokyo, Sony advanced 1.87 percent to 7,804 yen, Panasonic rose 1.40 percent to 1,046 yen, and Toyota was up 0.69 percent at 7,670 yen.
Nissan jumped 2.26 percent to 644.3 yen after its fugitive former CEO Carlos Ghosn accused the Japanese automaker and Japanese prosecutors of plotting against him, speaking at a Beirut press conference in his first public appearance since fleeing the country.