Tokyo shares rose 1.31 percent on Wednesday morning, tracking gains on Wall Street as investors scooped up shares and reversed recent losses on Japan's main equity markets.
The Nikkei 225 index at the Tokyo Stock Exchange climbed 110.18 points to 8,492.18 by the midday break.
The broader Topix index of all first-section issues gained 1.08 percent, or 7.68 points, to 715.92.
"There has been so much shorting of the major indexes of late that at some point, we will have to see some positions unwinding," CLSA equity strategist Nicholas Smith told Dow Jones Newswires.
But he added: "While profit growth at Japanese companies is on the whole outstanding, focus unfortunately remains totally on Europe and currency levels."
On Monday, the headline Nikkei index tumbled to its lowest close in six months, while the Topix dipped below the 700 level and its lowest since December 1983.
Worries about the eurozone continue to rise on fears about Spain's finances and a possible Greek exit from the 17-nation bloc.
Top European finance ministers vowed Tuesday to respond "speedily" to the continent's debt crisis as Madrid pleaded for help to prop up its struggling banking system and avoid a bailout.
Traders said the comments had little impact on the euro, which rose against the dollar and yen in Asia mainly on hopes of further easing measures following a European Central Bank policy meeting later Wednesday.
The euro bought $1.2492 and 98.44 yen in Tokyo trade, against $1.2450 and 98.03 yen in New York late Tuesday.
The dollar inched up to 78.80 yen from 78.72 yen.
On Wall Street, the Dow Jones Industrial Average added 0.22 percent to finish at 12,127.95, snapping a four-day losing streak.
In Tokyo, Olympus shares rose 1.20 percent to 1,347 yen after the Nikkei business daily said the camera and medical equipment maker was likely to swing back into the black in its current business year.
A separate report from Kyodo news agency said electronics giant Panasonic would inject as much as 50 billion yen ($630 million) into troubled Olympus, which has been struggling to move past a massive loss cover-up scandal that sparked lawsuits and the arrests of former executives.
Panasonic shares rose 2.55 percent to 522 yen.