As we all know, there is a reason why the Tang Dynasty was called the prosperous Tang Dynasty by later generations. At its worst, countless foreign envoys came to see it. It can be said that all countries have come to Korea, and Japan is naturally among them. Japanese envoys in the Tang Dynasty can be said to be the ones who have the most frequent contact with the Tang Dynasty. Their purpose is to learn all the technology, literature, military, agriculture, business and even dress styles that can benefit the Japanese archipelago. Compared with other countries and people, Japan always shows a strong sense of worship. Although later generations understood the reasons for their worship, it was still very useful in ancient times.
As for China's costumes, the attitude of Japanese envoys to follow the example of the Tang Dynasty was almost outrageous, because it was very uncomfortable to see a group of people wearing the same clothes as themselves and wearing a bun, but shaved their heads. However, at that time, Emperor Taizong felt that this was the style of a big country. Instead of punishing them, he gave them many court clothes, including samurai clothes. Japan's devotion to the Bushido spirit is admirable, so Japan is also interested in the samurai costumes of the Tang Dynasty, which were later sent back to Japan. I didn't expect the famous Japanese soldiers and generals in the Warring States period to be crazy about this kind of clothing, thinking it was a solemn symbol, in line with my aristocratic status, and the significance of this kind of clothing was also the spirit of Japanese Bushido, so they all changed into this kind of samurai clothing.
However, most of the costumes in the Tang Dynasty were silk and linen lined with some cotton, which was very bloated to wear. So the Japanese thought of a way to take out the cotton inside, leaving only a light coat, and then put this light coat on the outside of the armor, thus wearing a sense of majesty and leading the fashion.