After graduating from Oxford University, Mr Hunt spent two years in Japan teaching English and learning Japanese.
China is Britain's fifth largest trading partner, with trade between the two worth £59 billion in 2016.
Hunt at a meeting with Chinese Foreign Minister Wang Yi, said, "My wife is Japanese - my wife is Chinese".
"My wife is Chinese, sorry", he said, adding: "That is a bad mistake to make".
Hunt said Wang had made an offer "to open discussions about a possible free trade deal done between Britain and China post Brexit".
Wang said about 60 percent of China's trade surplus with the United States was created by foreign companies operating in China and that USA firms had reaped "huge profits" in the country.
The Foreign Secretary was hoping to use the visit to boost trade links and address sensitive issues including the human rights situation in Hong Kong. Free trade talks typically take many years to conclude.
Wang said that the fault for the current trade imbalance lied with the USA, pointing to its high levels of consumption, low savings rates and the global dominance of the dollar, Reuters reported.
He also reportedly argued that the USA has ultimately gained from its trade with China, because it has offered access to cheap products relished by American consumers.
His trip follows a visit by May earlier this year where £9bn worth of trade deals were signed and new measures were agreed to open up China to United Kingdom goods and services.
Trump imposed tariffs on billions of dollars in Chinese goods earlier this month, prompting retaliatory measures from Beijing. "We do not welcome nor do we accept other countries to interfere in China's domestic affairs", Wang said at a joint news conference.
Wang said the current tensions were initiated by the United States, and the two should resolve their issues under the World Trade Organization framework, rather than in accordance with USA law.
"China's door of dialogue and negotiation remains open, but any dialogue must be based on equality, mutual respect and rules". "Any unilateral threats and pressure will only have the opposite effect".