Around this time, maritime groups of pirates called Wako (meaning Japanese pirates) began to raid the coasts of the Korean peninsula and China (these are labeled the "early period Wako" to distinguish them from later pirate groups of the same name), and a request, called a Sakuho, from the Ming court that the pirates be brought under control was sent to Imperial Prince Kaneyoshi, addressed to the 'King of Japan'; Kaneyoshi thereby received a boost to his authority.
この頃、朝鮮半島や中国の沿岸などで倭寇（前期倭寇と呼ばれる）と呼ばれる海上集団が活動し始めており、懐良親王は倭寇の取り締まりを条件に明朝から冊封を受け、「日本国王」としての権威で勢力を強める。