Stories of the Japanese 01174 [End of the Northern and Southern Courts Period] King of Japan Ryokai

March, 25th year of Shohei / 3rd year of Oan (1370). There was a new development in diplomacy with the Ming dynasty. Prince Kaneyoshi of Kyushu began paying tribute to the Ming, styling himself as the "King of Japan."
Although the Muromachi Shogunate was the one governing all of Japan, why was Prince Kaneyoshi, who was merely a local regime governing Kyushu, invested as King by the Ming, the largest great power in Asia? To explain the circumstances, we must go back about two years.
Zhu Yuanzhang (1328–1398), who came from a poor peasant background, gained power during the Red Turban Rebellion, expelled the Yuan from North China, ascended to the throne as Emperor in January of the 28th year of Zhizheng (1368) by the Chinese calendar, and declared the founding of the Great Ming Empire.
Emperor Hongwu, formerly Zhu Yuanzhang, sent envoys to Japan immediately after his accession. He must have placed importance on foreign relations when establishing his new nation. Also, since the interests of the Ming and the Korean Peninsula were being threatened by the rampant Wokou pirates, it is thought that he wanted to request that their suppression be thoroughly enforced.
However, the first mission was killed by pirates somewhere in the Goto Islands, and their state letter was destroyed. The waters around Kyushu were that lawless at the time.
February, 24th year of Shohei / 2nd year of Oan (1369). The second mission from the Ming arrived. It was a seven-member delegation led by Yang Zai. The content of the state letter was:
"Pay tribute to the Great Ming Empire. Furthermore, if you leave the Wokou unchecked, we will send the Ming army to capture the King of Japan."
Although this state letter reached Prince Kaneyoshi safely, he was angered by its rudeness, beheaded five of the seven envoys, and detained the remaining two, including Yang Zai.
Three months later, the released Yang Zai fled back to the Ming and reported what had happened. Emperor Hongwu must have been furious, but in March of the 25th year of Shohei / 3rd year of Oan (1370), he persistently sent a third mission. The representative was Zhao Zhi, and the content of the state letter was the same as the second, ordering tribute and the suppression of the Wokou.
Prince Kaneyoshi, perhaps mistaking the Ming for the return of the Yuan because Zhao Zhi's surname was the same as "Zhao Liangbi" from the time of the Mongol invasions, ordered that Zhao Zhi be beheaded again. However, Zhao Zhi was a tough negotiator; he patiently explained that they, the "Ming," were a country newly built after driving out the Yuan, and that other countries were already paying tribute to the Ming,
"If you kill me, disaster will befall you."
he even stated, so Kaneyoshi finally decided to pay tribute to the Ming.
Prince Kaneyoshi is referred to as "King of Japan, Ryokai" in official Ming documents. It is unclear why "Kaneyoshi" was flipped to "Ryokai," but in any case, because a local regime in Kyushu had established diplomatic relations with the Ming by claiming to be the representative government of Japan, the Muromachi Shogunate would struggle to correct the course.