It is also recorded that, although a friendship with Japan was rejected in 840, trade between ordinary citizens was allowed the next year and Koreans formed close friendships with government officials in Kita-Kyushu (Northern Kyushu) and Nyuto-priests (priests who went to China to study) through trade.
また、この間、840年（承和(日本)7年）には日本との通交を拒否されたが、翌年には民間の交易が認められ、北九州の官人や入唐僧などと貿易を通じて深くかかわっていたことが記録されている。