Investors are now keeping their eyes on the talks that will resume in Washington this week.
"There are some signs of easing in US-China tensions but this negotiation is essentially the beginning of serious bilateral frictions," warned Kenji Yoshikawa, senior economist at Mizuho Securities.
"We must watch out for a longer-term effect that a slowdown in the Chinese economy could have on the global economy and the stock market," he said in a commentary.
Market players are also watching Japan's trade balance in January due on Wednesday, analysts said.
"A decline in exports is expected to get sharper, but if the pace is better than market expectations, that would prompt optimism that China-linked companies' performance may pick up," Tsuyoshi Nomaguchi, strategist at Daiwa Securities, said in a commentary.
The dollar fetched 110.55 yen, against 110.43 yen in New York on Friday. Automakers were among the winners, with Toyota gaining 0.76 percent to 6,655 yen, Honda up 1.03 percent at 3,003 yen and Nissan rising 1.40 percent to 948.1 yen.
Bridgestone was up 4.93 percent at 4,402 yen after it announced a major share buy-back.
Sharp jumped 9.87 percent to 1,325 yen after the company announced the release of three new models of its tiny home-use robot.
SoftBank Group added 0.43 percent to 10,375 yen on a report that the telecoms and investment group is closing in on an investment in German online travel guide and booking website GetYourGuide.