The Nikkei 225 index at the Tokyo Stock Exchange, which soared 1.24 percent on Wednesday, lost 46.08 points to stand at 8,514.03 by the break.
The Topix index of all first-section issues slipped 3.75 points or 0.50 percent to 739.24.
The euro fetched $1.2923 and 99.12 yen in Tokyo morning trade, down from $1.2941 and 99.28 yen in New York late Wednesday. The dollar was flat at 76.70 yen.
Profit-taking was setting in after the previous day's strong gains, said Daiwa Securities senior market analyst Yumi Nishimura.
"There are hopes for bullish US economic indicators, including ADP employment data later today, which will likely furnish the Nikkei with some sentimental support for the rest of the day," she told Dow Jones Newswires.
Payrolls firm ADP is to release private-sector hiring data for December ahead of the closely watched government jobs report Friday.
Honda was up 1.35 percent at 2,476 yen and Toyota gained 0.26 percent at 2,651 yen following Wednesday's sharp run-up, illustrating some follow-through buying amid broader market weakness.
The shares were seen benefiting from solid December sales announced by all three Detroit automakers.
US blue chips pushed higher Wednesday but the broader market was virtually flat amid hesitant trade.
The Dow Jones Industrial Average finished up 0.17 percent at 12,418.42 while the broader S&P 500 was flat, adding just 0.02 percent to 1,277.30.