Why is there a small pillow behind Japanese women's kimono?

In some TV plays in War of Resistance against Japanese Aggression, we can always see the traditional Japanese costume-kimono. At this time, I can't help thinking: Why is there a small pillow on the back of kimono? What's the use of this little pillow?

Kimono is developed from the original clothing in Japan. At first, the traditional Japanese women's dress was called "through-the-head dress"-a hole was dug in a large piece of cloth enough to pass through the head, so that the wearer could put the clothes on his head. Then tie the cloth hanging under the armpits on both sides with a belt and match it with a skirt.

Men's wear is similar to women's wear and is called the "big flag". Later, because these costumes and Hanfu merged with each other in Wudi, China, they became the "five clothes". Later, "Wufu" was once again influenced by the traditional culture of China, and it was called "kimono" from the Tokugawa Ieyasu period. That is the earliest form of kimono.

During the Tang Dynasty, China welcomed foreign emissaries with an open, humble and tolerant attitude, and sent emissaries to spread China's culture all over the world. Among them, Japan urgently needs technical support.

Japan sent Tang envoys to China three times, leaving a large number of textile craftsmen for China. They brought their skills to Japan, as well as the traditional culture and costume features of China. Therefore, Japanese kimono has strong cultural characteristics of China.

In the Taoshan era, Japanese women liked to tie their waists with thin ribbons, but it was not popular and gradually faded. It was not until Toyotomi Yoshiyuki's time that China's loincloth spread to Japan. These corsets are very delicate and often attract people's attention.

However, it is very troublesome to tie such a wide waist, and the beautiful lines at the waist become a big belly because of the knot. So, these Japanese women decided to tie a knot behind their backs. Gradually evolved into a later small pillow.