Tokyo stocks closed 0.83 percent lower Monday, shedding early gains as profit-taking kicked in after the benchmark Nikkei 225 index hit its highest level since the 2011 quake-tsunami disaster.
The Nikkei finished 89.10 points down at 10,599.01, while the Topix index of all first-section shares lost 0.84 percent, or 7.45 points, at 881.06.
The retreat follows a 2.82 percent surge Friday, the first trading day of 2013, as the yen tumbled on relief US lawmakers had cut a deal to avert the fiscal cliff of tax hikes and spending cuts that threatened to tip the economy into recession.
The Nikkei ended 2012 at its highest level since the disasters on March 11, which sparked the worst nuclear crisis in a generation.
"With the major indexes having run up so far so fast, alarm bells have sounded about technical overheating," an equity trading director at a foreign brokerage told Dow Jones Newswires.
"Some players want to take some cash off the table...but demand remains strong overall, and this does not look like a tipping point in terms of a more profound selloff."
The greenback bought 87.73 yen in Tokyo afternoon trade, down from 88.15 yen in New York on Friday, after earlier hitting a peak of 88.41 yen, its highest level since mid-July 2010.
The euro was also weaker against the Japanese currency at 114.33 yen from 115.19 yen, while it slipped to $1.3034 from $1.3067.
US data Friday showed a modest 155,000 jobs were added to the world's biggest economy in December, not enough to spark great optimism but a sign of strength given the unsteady political policy climate of recent months.
In Tokyo, shares of Aozora Bank tumbled 10.07 percent to 250 yen following a report that the lender's leading shareholder, investment giant Cerberus, plans to sell most of its stake.
Mobile phone carrier Softbank was down 1.91 percent at 3,065 yen, off for the third straight session, amid reports Clearwire is trying to block its $20 billion takeover of Sprint Nextel.
Softbank has offered to buy 70 percent of Sprint Nextel, which is Clearwire's largest single shareholder.
Honda dropped 1.22 percent to 3,230 yen and Canon lost 2.63 percent to 3,330 yen, while Uniqlo cheap chic clothing operator Fast Retailing gained 2.74 percent to 22,810 yen.