Tokyo stocks erased early gains and closed down on Monday as concern over fresh Covid-19 spikes in some Asian countries weighed on the market.
The benchmark Nikkei 225 index fell 0.92%, or 259.64 points, to 27 824.83 while the broader Topix index lost 0.24%, or 4.56 points, to 1 878.86.
Tokyo shares opened higher, trailing rallies on Wall Street, brokers said.
But shares soon fell into negative territory "partially due to concerns over recent increases in coronavirus infections in Asia", Yoshihiro Okumura of Chibagin Asset Management told AFP.
"Also, a recent price hike in raw materials discouraged investors from actively buying shares," Okumura said.
"As the earnings season is ending, investors are looking for new factors," Okumura said, adding trading was expected to remain stagnant for the time being.
The dollar fetched 109.32 yen in Asian afternoon trade, against 109.34 yen in New York Friday.
In Tokyo trading, Seven & i Holdings dropped 3.07% to 4 790 yen after it completed its $21 billion acquisition of convenience store chain Speedway, although US antitrust officials reportedly warned the deal may be illegal.
Tokyo Electron, a major producer of tools to build semiconductors, plunged 3.68% to 44 700 yen.
Honda lost 2.67% to 3 238 yen after the carmaker forecast a drop in annual net profit.
Toyota jumped 2.00% to 8.648 yen and Sony rose 1.02% to 10 330.