Tokyo stocks fell 0.61 percent Friday morning after a slate of weak Japanese data and a turndown on Wall Street driven by renewed Ukraine-Russia tensions.
The benchmark Nikkei 225 index slipped 94.78 points to 15,365.08 by the break, while the Topix index of all first-section shares was down 0.41 percent, or 5.24 points, at 1,275.50.
Profit-taking was digging into the Nikkei's gains following a rise in the Japanese market, analysts said.
"The Nikkei's steady rally for most of the last three weeks still leaves room for profit-taking on the back of the weaker dollar," said Tsuyoshi Nomaguchi, equity strategist at Daiwa Securities.
"But hopes for more government pension fund buying of domestic stocks should keep prices from falling too far."
Investors were also looking to possible details next week on plans to cut Japan's corporate tax rate, a key plank of Prime Minister Shinzo Abe's economic growth plans.
"The government's intention is to lower the tax rate to a more accommodating level while broadening the base, but the political pitfalls are numerous, and thus the debate will pose a good test for the Abe Administration's political strength," CLSA equity strategist Nicholas Smith told Dow Jones Newswires.
Just before the market opened, the Japanese government released a set of data that showed consumer spending dropped and factory production slowed sharply in July, leading to questions about the country's recovery.
Toyota edged up 0.10 percent to 5,941.0 yen and Canon was down 0.64 percent at 3,389.5 yen, while market heavyweight Fast Retailing, operator of the Uniqlo clothing chain, fell 1.11 percent to 32,300.0 yen.
In currency markets, the dollar weakened 103.70 yen, from 103.75 yen in New York.
US shares were pressured by news that Russian forces were inside Ukraine helping support pro-Kremlin separatists who have been fighting against Kiev's rule since April.
NATO said at least 1,000 Russian troops were on the ground in Ukraine. Moscow insisted none of its soldiers were on Ukrainian soil.
The tensions cast a cloud over positive economic news. The Commerce Department said the US economy expanded at a 4.2 percent annual rate in the second quarter, revising upward its 4.0 percent July estimate.
However, on Wall Street the S&P 500, which ended above 2,000 for the first time this week, pulled back from Wednesday's record close, shedding 0.17 percent. The Dow lost 0.25 percent and the Nasdaq dropped 0.26 percent.