In the Ming Dynasty, the Japanese invaded China and were roughly divided into two periods. During this period, the area and degree of the infestation also varied. In the early stage, it was about the Hongwu and Yongle years. The chaotic areas are mainly in coastal areas such as Liaodong, Shandong, and Zhejiang, and harassment by small groups is the main mode of activity. Later, around the Jiajing period, the Japanese invaded the southeastern coastal areas on a large scale.

In fact, the Japanese were rampant not only in the land of the Ming Dynasty, but also in the mainland.

At that time, Japan was in the background of "going down and going up", and bandits were rampant. Those "envoys" from Japan often dressed as Confucian monks and did some bandit acts behind their backs. Over time, the common people of the Ming Dynasty also noticed these wolves under sheep's clothing and no longer believed in the Japanese.

For example, the Japanese envoys during the "Ningbo Tribute Campaign" were bandits who pretended to be envoys.

“貢使至臨清，掠居民貨。 ”

“其王源義政移書北韓王，令轉請遣使謝罪，廷議使臣不得仍前肆擾。 ”

“源義高遣使來京，還至濟寧，其下仍持刀殺人，詔嚴防禁。 ”

From these texts, we can see that it has become "commonplace" for the Japanese to pretend to be tributary envoys and come to the Ming Dynasty to loot.

But if this is the case, why did the Ming Dynasty government not go to war against Japan?

This is probably because although the Chinese emperor had the ambition of "expanding the territory", he did not have the sight of expanding overseas territories. Before Zhu Yuanzhang died, he instructed Zhu Yunwen not to attack more than a dozen "countries that do not conquer", including Japan, and he was influenced by this thought.