In 4334, that is, in December 1637, the diplomatic envoy of the Tokugawa shogunate of the Wa kingdom, Naotaka Ii, arrived at the port of Tianjin on a Chinese merchant ship.

Naotaka Ii knew that it had been more than 200 years since the last time the Japanese government officially sent an envoy to China.

The last time the Wa Kingdom established formal diplomatic relations with China was during the reign of Ashikaga Yoshimitsu Shogun during the Muromachi shogunate.

The great man who unified the north and south of Japan and once coveted the emperor's throne, in order to promote the development and prosperity of his country, accepted the canonization of the Ming Dynasty very humiliatingly, and was a vassal to the Ming Empire, and signed the "Exploration and Trade Treaty" with the Ming Empire, creating a tributary trade that played a great role in the economic development of the Japanese Kingdom.

Although the Tokugawa shogunate had a lot of negative comments about the prince who was posthumously crowned Emperor Taishang and led Japan to prosperity and prosperity more than 200 years ago. But now in this situation, the Tokugawa shogunate had to find ways to hope that it could follow the old path of Ashikaga Yoshimitsu, obtain the canonization of the Chinese Empire, and establish formal diplomatic relations with the Chinese Empire, in order to obtain the economic and military support of the Chinese Empire.

Because Japan, which had always resisted the establishment of formal vassal relations with China, to this day, after the Chinese Empire took full control of the East China Sea, on the one hand, because the Chinese Empire punished the former Japanese state for its disrespect to the Chinese Lordship, and completely blocked foreign trade with the Tokugawa shogunate. On the other hand, the Chinese Empire openly carried out large-scale smuggling activities with local daimyos, selling advanced iron cannons and large cylinders to local daimyos. And he gave strong support to the Shimabara Rebellion, providing them with a large amount of food and weapons, and even sending instructors to train the Shimabara Rebellion's army.

As a result, the Tokugawa shogunate has suffered severe economic damage and entered a severe recession. On the other hand, the daimyo in various regions, who were already very dissatisfied with the "arbitrary politics" of the Tokugawa shogunate, became stronger and began to act as a result of the arms trade with China. What's more, the more than 100,000 shogunate army led by Matsudaira Nobutsuna was completely defeated by the more than 30,000 trained iron artillery troops of the Shimahara rebels not long ago.

The Tokugawa shogunate, whose rule was in a precarious and dangerous situation, was keenly aware of the shadow of the Chinese Imperial Government behind the disgruntled daimyo in various regions and the rebellious people of Shimabara, which consisted of peasants and cultists.

It was under these circumstances that Tokugawa Iemitsu sent Naotaka Ii, who had achieved considerable diplomatic success, to China, hoping to establish friendly relations with China on the example of Ashikaga Yoshimitsu and receive help and support from the Chinese Lord.

In Naotaka Ii's view, the Chinese imperial court has been a self-respecting regime since ancient times. He believed that as long as he gave enough face, as long as he put his posture low enough, then the shogunate's demands would definitely be satisfied. And from the information collected by Naotaka Ii, it seems that the Chinese Empire, the new empire that replaced the Ming Dynasty, would definitely be very happy to accept the shogunate's request if it could get the official tribute of the Wa State soon after the founding of the country.

Looking at the new with old eyes makes a serious mistake.

Naotaka Jing sees the Chinese Empire as a feudal empire like the Ming Dynasty, so there will be serious errors in his judgment. Not to mention the things he saw after being rescued by the armed merchant ships of the Chinese Empire because of the leakage of the tributary ship on the sea route of the tributary, which was beyond his comprehension. When he arrived in Tianjin, everything he encountered was completely different from what he had imagined, and it completely changed his view of China.

"As soon as I arrived in Tianjin, I discovered a terrible truth. The Chinese Empire's harsh attitude toward our country was probably due to the shogunate's acquiescence to the Satsuma Domain's annexation of the Ryukyus. ”

"The rule of the Chinese Empire in the ports was now carried out uniformly by a department called the customs office. Contrary to what I had imagined of the local government giving to tributary envoys, I was sent to a tall and busy customs building by the captain of the great ship I was aboard as a state envoy, and then confined to a small room for a long wait. ”

"When I was dizzy from hunger, a small, dark-skinned officer came to meet me in this small room."

"One of the obvious facts I discovered along the way is that the Chinese seem to be changing their traditions. Because on the way from the dock to customs, I saw a lot of Chinese wearing very simple and plain clothes with completely different styles. Even those who wear old-fashioned Chinese clothes are no longer wearing that long hair. ”

"But it's not the change of clothes that surprised me the most. What surprised me the most was that the Chinese were making widespread use of a mechanism that was smoking all the time. I saw those huge steel mechanisms on the docks, and it was very easy to carry away the huge cargo on the huge ship I was on. ”

"I must also describe the Chinese merchant ship I am on. Because the captain of the huge Chinese merchant ship with many huge cylinders told me that his ship was a small ship that is more common in China. The huge ship, which is much larger than any ship in our country, is only more than 2,000 tons according to Chinese calculations. ”

"It wasn't until I arrived at the port of Tianjin that I was convinced of his claim. Because I did see a lot of huge ships in Tianjin Port that didn't use any sails or oars at all, and smoked all the time. There were indeed a lot of boats in the harbor that were much bigger than the one I was on. ”

"The thin black man who came to see me was able to speak my Chinese with a thick accent. From his accent, I thought he was a native of the Satsuma Domain. Unexpectedly, when I was talking to him in my native language, he told me in a very mocking tone that the Satsuma Domain, which was a Japanese daimyo, no longer existed. Two years earlier, the Tense-to-Korean army had razed the Satsuma Domain and executed the entire Shimazu family. The Tendai Dynasty had severely punished all the Japanese who had invaded the Ryukyu Kingdom, which was a feudal domain of the Tendai Dynasty. ”

"Based on the words of the customs officer, I deduced why two years ago the Chinese fleet suddenly appeared in the sea outside the river, shelled Edo Castle, and sank all the ships. It turned out that the Chinese Empire had exterminated the Satsuma Domain as early as two years ago because of the Satsuma Domain's invasion of the Ryukyu Kingdom. Today, Kagoshima is already a base of the Chinese Empire. ”

"The shogunate has been kept in the dark for several years, and has always believed that the Satsuma domain, like some coastal daimyos, has become distracted from the shogunate because of the purchase of a large number of weapons. Now it seems that it is quite possible that the Shimazu family was wiped out by China is a fact. ”

"How can I reasonably explain the shogunate's acquiescence to the rebellious behavior of the Satsuma Domain, and dissociate the relationship between the shogunate and the Satsuma domain, which has become a matter of great concern for me now."

-- 1884, Naotaka Ii, "Tributary Diary", "Research Series on the History of Naturalization in the Four Eastern Provinces", Edo Commercial Publishing House