By Agence France-Presse
The benchmark Nikkei 225 index slipped 0.39 percent or 88.97 points to 22,762.78 in early trade, while the broader Topix index was down 0.53 percent or 9.51 points at 1,779.53.
"Concerns over a US-China trade war are weighing on the market, prompting profit-taking sales," Yoshihiro Ito, chief strategist at Okasan Online Securities, said in a commentary.
The fall came after US stocks retreated over tit-for-tat tariff announcements by Washington and Beijing ignited a trade war that could spread, with the Dow closing down 0.3 percent at 25,090.48.
About an hour before the opening bell in Tokyo, a 5.3-magnitude quake struck near Osaka in western Japan, but there were no immediate reports of major damage or risk of a tsunami, officials said.
The dollar fetched 110.60 yen in early Asian trade, against 110.68 yen in New York late Friday.
Sony was down 1.28 percent at 5,376 yen and Panasonic slipped 1.34 percent to 5,372 yen.
Mitsubishi UFJ Financial was down 0.75 percent at 6,537 yen.