Tokyo stocks closed lower on Monday after sharp rallies last week on hopes for a phased reopening of the US economy, with investor focus now on the number of local virus cases.
The benchmark Nikkei 225 index lost 1.15 percent, or 228.14 points, to end at 19,669.12, while the broader Topix index fell 0.70 percent, or 10.13 points, to 1,432.41.
In Japan, the number of coronavirus cases topped 10,000 on Saturday, and "this week the government is expected to study the effect of its request to refrain from going out", which was expanded to the whole country on Thursday, Daiwa Securities said in a commentary.
The virus has killed more than 170 people so far, according to the health ministry.
Whether the government will extend the state of emergency period beyond May 6 is in focus, and investors "will be watching the number of domestic cases this week", it said.
The dollar fetched 107.85 yen in Asian trade, against 107.59 yen in New York late Friday.
In Tokyo, exporters were lower, with optical precision maker Olympus dropping 2.69 percent to 1,697 yen and Canon 0.75 percent to 2,243 yen.
Toyota fell 1.79 percent to 6,635 yen and Honda dipped 0.72 percent to 2,451.5 yen.
Some pharma companies were also lower, with Daiichi Sankyo losing 3.67 percent to 7,373 yen and Chugai 3.87 percent to 13,260 yen.
Ten minutes before the opening bell, official data showed Japan's trade surplus dived 99 percent in March from a year earlier as coronavirus woes hit exports to its major trading partners.