Tokyo stocks closed lower on Wednesday after the first US presidential debate between Democrat Joe Biden and President Donald Trump, which turned into a shouting match.
The benchmark Nikkei 225 index fell 1.50 percent or 353.98 points to end at 23,185.12, while the broader Topix index dropped 1.97 percent or 32.61 points to 1,625.49.
"After the presidential debate, concerns over a (potential) political vacuum due to issues around Mr Trump caused falls in US features, with the Nikkei slipping further," Okasan Online Securities chief strategist Yoshihiro Ito said in a commentary.
Telecom operator NTT closed down 3.60 percent at 2,150 yen, a day after it announced a takeover of its mobile phone unit on concerns the deal could have negative impact on NTT's financial conditions.
Its phone unit NTT Docomo climbed 20.91 percent to 3,885 yen, near the 3,900 yen price NTT will pay in the deal.
Its smaller rival and wireless newcomer Rakuten was up 0.89 percent at 1,132 yen. After the market close it announced a 5G wireless service at a much cheaper price than domestic rivals.
Among other major shares, Toyota was down 2.54 percent at 6,932 yen, Uniqlo casual wear operator Fast Retailing was down 0.36 percent at 65,860 yen, and Sony ended down 2.04 percent at 8,032 yen.
The dollar fetched 105.49 yen in Asian trade, against 105.68 yen in New York late Tuesday.