Japan's Nikkei share average edged up on Wednesday, getting a lift from further gains on Wall Street and as investors bet a weekend election would usher in continued political and monetary stability.
The Nikkei was up 0.1 per cent at 21,354.56 points at the end of morning trade, probing fresh 21-year highs and on track for its 12th straight winning session.
The broader Topix was slightly higher, up 0.03 percent at 1,723.82.
Underpinning sentiment, the US blue-chip Dow Jones Industrial Average closed at a record high on Tuesday, after briefly breaking above the 23,000-point mark for the first time.
“US stocks have momentum now, and it's carrying over to other markets,” said Norihiro Fujito, a senior investment strategist at Mitsubishi UFJ Morgan Stanley Securities. "Investors, including foreigners who were significant net sellers in recent months, are buying ahead of Japan's election on Sunday.”
He added that the buying “is not just short-covering, but rather investors taking new long positions.”
Japanese Prime Minister Shinzo Abe's coalition is on track for a roughly two-thirds majority in Sunday's general election, a survey by Kyodo news agency showed, as its conservative rival led by Tokyo Governor Yuriko Koike appeared to lose momentum.
Japanese companies overwhelmingly want Abe's ruling coalition to stay in power but about two-thirds hope that it loses seats, according to Reuters poll published on Wednesday.
Stock gains were capped by wariness over corporate scandals at some large firms.
Shares of Kobe Steel Ltd shed 2.9 per cent, resuming their slide after rising in the previous session. The steelmaker's stock has shed over 39 per cent this month, since its data falsifying scandal came to light.
Kobe Steel said Tuesday it has been asked by the US Justice Department to submit documents related to its data fabrication scandal, as the company delivers its products to a wide range of industries in the US from car makers to airlines.
Nissan Motor Co shares slipped 0.5 per cent.
Nissan conducted uncertified vehicle checks as recently as last week even after revealing the widespread misconduct at its domestic factories, two sources with direct knowledge of the matter said on Wednesday.
Japan's second-largest automaker has recalled all 1.2 million new cars it sold in the domestic market over the past three years after discovering final vehicle checks were not performed by certified technicians.
Other automakers rose, with Honda Motor Co up 0.2 per cent and Toyota Motor Corp up 0.6 per cent.
The JPX-Nikkei Index 400 added 0.1 per cent to 15,262.48.