The Nikkei share average ended 0.36% lower at 27,424.47, erasing earlier gains of 0.52% after strong financial results from heavyweights including Tokyo Electron.
The broader Topix slid 0.49% to 1,915.63 after rising as much as 0.56% earlier.
Japan is struggling to suppress its fifth wave of COVID-19 infections. The government is set to extend its state of emergency in the capital Tokyo and other regions to Sept. 12, and expand the curbs to seven more prefectures, public broadcaster NHK reported on Monday.
Tokyo announced 2,962 new daily cases on Monday, after a record 5,773 on Friday.
With the Delta variant making it hard to see when infections might peak out, “it’s difficult to actively chase stocks higher,” said a market participant at a domestic securities firm.
Tokyo Electron dropped 0.73%, retreating from an initial jump of 3% despite revising up its earnings outlook.
Pandemic worries weighed on reopenings plays including restaurants, department stores and travel-related stocks.
Air transport was the worst-performing Topix subsector, falling 2.34%.
Services lost 0.97%, after earlier climbing 0.62%, while retailers dipped 0.30%, paring earlier gains of 0.49%.
Shippers, however, led the six gainers among the 33 subsectors with a 1.62% rally. Kawasaki Kisen topped Nikkei jumping 3.51%.
Shippers have been on a tear since the end of last month, when Mitsui OSK Lines made a big upward revision to its outlook. The stock rose 1.36% on Tuesday.
The sector has rallied 38.24% so far in August, and is set for its best month ever, compared to a 0.77% gain by Topix.
“When traders look at the performance in shippers, there still seems to be an urge to buy something,” said a market participant at a domestic securities firm.
