South Korean President Moon Jae In has sent a personal letter to Japanese Emperor Naruhito, a South Korean government source said Tuesday.The substance of the letter was not immediately known.Prime Minister, who arrived in Tokyo on Tuesday to attend the enthronement ceremony, will also deliver a personal letter from Moon addressed to Japanese Prime Minister Shinzo Abe when they meet during his three-day visit, according to the source.Over a year has passed since the last summit between Moon and Abe was held on the occasion of the U.N. General Assembly in September last year. At the time, th…READ FULL ARTICLE