The Nikkei fell 1.09 percent Monday as the yen's strength and caution over the situation in Iraq gave the market a chance to take a breather, as some investors opted for profits after a decent run of gains recently.
The Nikkei 225 index lost 164.55 points from Friday to close at 14,933.29, while the broader Topix index of all First Section issues on the Tokyo Stock Exchange ended down 9.29 points, or 0.75 percent, at 1,234.68.
Some analysts here pointed to the worst case scenario in Iraq being one that leads to oil facilities being destroyed and supply chains being damaged, although others speculated the conflict would not escalate to such levels as the U.S. is considering holding talks with Iran on how to ease the situation.
"The situation in Iraq could lead to destruction of supply facilities in the second-largest oil producer, and if U.S. troops launch air strikes it may impact Japanese stocks," said Shoji Hirakawa, chief equity strategist at Okasan Securities Co.
Fund managers here also pointed to nervous investors being quick to hit the sell button when there are negative catalysts overseas, while others pointed to the market here being overbought in the short term.
"Once investors see negative catalysts overseas, they get jumpy and sell," said Koji Toda, chief fund manager at Resona Bank Ltd. "They are cautious about chasing higher prices because the market has been overbought in the short term."
Yoshihiro Okumura, general manager at Chibagin Asset Management concurred with the latter statement saying, "The market is short- term overbought and there isn't too much we can expect from a domestic investor-centered rally."
"But recent Nikkei performances have been encouraging. If and when foreigners do return, the effect will likely be dramatic," Okumura said.
In times of geopolitical uncertainty investors often switch to the yen as a safe haven, this pushing up its value. The U.S. dollar dropped to 101.76 yen from 102.04 yen in New York Friday.
A stronger yen is bad news for exporters and firms with a wide exposure to overseas markets as it diminishes profits when they're repatriated.
Honda Motor skidded down 1.3 percent to finish at 3,511 yen, while consumer electronics maker Panasonic Corp. retreated 1.5 percent to close at 1,182 yen.
Electronics and semiconductor maker Tokyo Electron advanced 2.5 percent to 7,000 yen, following Intel raising its second-quarter revenue projection last week. Chip tester maker Advantest also closed in positive territory on the news, gaining 0.6 percent to close at 1,260 yen.
Real estate shares came under pressure Monday, with Sumitomo Realty & Development retreating 2.3 percent to 4,345 yen, while Mitsui Fudosan closed down 2.2 percent at 3,236 yen.
Japan Tobacco was a notable decliner on Mondayh's market, losing 1.5 percent to 3,616 yen, following the firm saying its domestic sales in May had slumped 10.3 percent in the month on year.
Trading volume on Monday dropped to 1.82 billion shares on the Tokyo Exchange's First Section, down from Friday's volume of 2.71 billion shares, with declining issues beating advancing ones by 1, 147 to 518.