Trading with China was their only chance to get out of their predicament, so they naturally supported the merchants of their own domain to participate in the smuggling trade. This is the same reason as Elizabeth's support for pirates, but there is no way to do it. However, the shogunate's successive sanctions led to tensions with the powerful feudal clans. Later, the shogunate accepted the opening of the country and reluctantly eased relations, but the shogunate held the customs in its hands and demanded that the feudal states that opened the port must report to the shogunate, and the shogunate sent the customs commission to manage the port. As a result, the largest benefit in foreign trade, tariffs, was taken away by the shogunate.

The contradictions have long been irresolvable, the more prosperous the trade, the more dissatisfied the powerful vassal becomes, and war is a matter of time. As long as there is a spark, wildfires will burn the prairies. The fuse was an accident, a British ship broke into the Chōshū Domain's Shimonoseki to transport Indian cotton, but because the shogunate did not accept direct trade with British merchant ships, it decided to seize the ship, the British did not cooperate, and the Shimonoseki pursued a request for the Choshu Domain to send troops to suppress it, but the Choshu Domain let go of the British merchant ship without authorization. The shogunate was dissatisfied, and demanded that the Choshu domain sanction some of the feudal lords involved. The Choshu clan refused to accept it, and the two sides were tense, and the lord of the domain, Mori Kei, had just finished his visit. At this time, someone told the shogunate that the British ship was not transporting cotton, but weapons. The Choshu Domain colluded with the Yiren and had bad intentions.

The shogunate asked Mori to come to Edo to explain, but Mori refused on the grounds that it was not in accordance with the system, and he had just finished his visit to Edo and had no reason to go to Edo again, in fact, he was also afraid. It is true that the Chōshū Domain had ties with the British, and economically, because the cotton sent by the British was cheaper and the Chinese merchants sold it more expensive, and the Chōshū Domain profited a lot from smuggling with the British. It's just that this time, the British didn't know what was wrong with their brains and broke into the port of Shimonoseki, which was controlled by the shogunate.

The shogunate severely reprimanded the Choshu clan on the grounds that the Maori clan was respectful and the Choshu clan was disrespectful, and then after communicating with other powerful clans, it was found that there were not many people who supported the Choshu domain, and the shogunate had long been dissatisfied with the unauthorized passage of the southwestern feudal domain, which not only meant that the tariffs were reduced, but there were also unknown risks, especially since they were in defiance, which was tantamount to openly breaking the law of seclusion and challenging the prestige of the shogunate. However, the collusion between the powerful feudal clans in the southwest has always made the financially strapped shogunate jealous.

This time, the foreigners openly broke through the barrier, putting the Choshu Domain in a disadvantageous position, and the shogunate decided to make an example of the chickens and monkeys, and gathered 20,000 soldiers to crusade against the Choshu Domain.

But the result was defeated, and the defeat was killed by 8,000 soldiers of the Choshu domain, and the battle between the two sides was not a Japanese war in the traditional sense, but a firearms era war that used rifled guns and explosive cannons, but the Choshu clan obviously had a deeper understanding of firearms, and their army organization was more scientific.

After the defeat of the shogunate, its prestige was greatly reduced, and at this time, many feudal lords saw that the shogunate could not defeat even a strong domain, and they were no longer afraid of the shogunate.

Although the Choshu Domain defeated the Shogunate, they knew that they had no confidence to challenge the Shogunate head-on, and they were worried that the Shogunate would continue to crusade, so they began to win over other feudal lords, and the Satsuma Domain, which also attached great importance to Rangaku, and the Nagasu Alliance, agreed that if the Shogunate came to attack, they would fight the enemy together.

After the defeat of the shogunate, they realized that it was impossible to defeat these feudal lords with traditional samurai, so they began to procure arms and train new troops. The actions of the shogunate made the Choshu domain appear that the shogunate was intent on attacking all the powerful feudal clans in the southwest, and even all the foreign daimyos, causing panic throughout Japan.

After contacting the Choshu Domain, he persuaded the Satsuma Domain to take the initiative, and then won over the Chikuzen Domain.

At the end of the Warring States period, Kuroda Nagamasa became a daimyo of 520,000 koku before he entered the feudal domain, and until now, the Fukuoka Domain, which is controlled by the Kuroda family, is the largest feudal kingdom in Kitakyushu. In the southern part of Chikuzen Province, Chikugo Province is home to Japan's best Miike Coal Mine, where coal mining, transportation, and steam power are easier to use, and combined with the strong manpower and material resources of the domain, Fukuoka has established a large number of factories such as silk reeling factories and spinning mills. However, the products they produced were subject to tariffs imposed by the shogunate, which greatly affected profits, so they were dissatisfied with the shogunate.

Although the Tosa Domain was also a reformed feudal kingdom that had become strong through maritime trade, they did not want to be an enemy of the shogunate, and when the fallen shogunate soldiers came to the Tosa Domain, they were persuaded by Sakamoto Ryoma and other feudal lords to defect. Tosa's defection brought the prestige of the shogunate to the bottom. At this time, the Shogunate faction did not go straight to attack the shogunate, but expanded in Kyushu, Shikoku and other places.

The Satsuma Domain annexed the Hyuga Fertile Domain of Hyuga Province and unified the southern part of Kyushu Island.

The Hizen domain captured Nagasaki, which was under the control of the shogunate.

Based on Kumamoto Castle, the Kumamoto Domain occupied the territories of Higo Province and Bungo Province, and annexed Bunzen Province.

Although Chikugo Province was also a powerful country, the development of the Miike Coal Mine in the territory made Chikugo Province's economy stronger than that of its neighbors, and although coal mining was monopolized by the shogunate and the mines were dispatched to manage it, the coal mine production brought prosperity to Chikugo Province. However, Chikugo Province itself did not have a strong feudal domain, but was divided into the Kurume Domain of the Arima Toyo clan with 210,000 koku and the Yanagawa Domain of the Tachibana clan with 110,000 koku. Therefore, fearing that the Hizen Domain would be attacked by the Shogunate faction and being annexed by the Kumamoto Domain, he chose to pledge his allegiance to the Fukuoka Domain of Chikuzen Province and merged into the historical Tsukushi Province.

The main way of annexation was to annex the declining Otomo clan, which had become a retainer of the Tokugawa family, to subjugate the small feudal lords of the Wafi Domain, and to expel the Ogasawara Nakatsu Domain of the Bunzen Province and the pro-shogunate genealogy daimyo of the Ogasawara Okura Domain.

The island of Kyushu is divided into four domains: Hizen Domain in the west, Fukuoka Domain in the north, Kumamoto Domain in the east, and Satsuma Domain in the south.

The Tosa Domain of Shikoku, with the support of the Choshu Domain, defeated the four feudal domains of Iyo Province, Matsuyama, Uwajima, Ozu, and Imabari, and subdued Sanuki and Awa, completing the unification of Shikoku Island.

The Choshu Domain was not idle, first conquering Iwami Province, a territory directly under the Shogunate, and seizing the Iwami Silver Mine; Then he captured the territory of the Matsudaira clan, the shogunate's pro-feudal clan, and Izumo Province. The Hiroshima Domain, which ruled Aki Province and Bigo Province, and the power of the Mori clan of the Choshu Domain, which had been subjugated, had basically returned to the Sengoku period and became the most powerful domain in the southwest.

The four great feudal domains divided the island of Kyushu, the Tosa domain unified the island of Shikoku, and the Choshu domain conquered the Chinese region, and at the same time formed an alliance and agreed to fall. Of course, the shogunate could not tolerate such a rebellion, and declared a rebellion of the four feudal domains and recruited the feudal states to fight against them. The four feudal states united with Choshu and Tosa to actively respond to the war.

The shogunate's army has also gathered in the area of Bichu, and a decisive battle is inevitable.

Due to the long-term employment of lower-class Japanese samurai by Chinese overseas companies, both the shogunate and the shogunate faction had a large number of formally trained samurai, and with these samurai, both sides established modern armies. The Choshu clan was stronger because they studied more thoroughly, and their feudal lord Yoshida Shoin studied in China long before China began recruiting Japanese samurai.

At that time, Yoshida Shoin was surprised to hear from Chinese smugglers that China had recruited nine million troops to fight against the Xiyi, and it was difficult for him to imagine that a country could arm nine million samurai. This kind of pomp and circumstance made him ignore the shogunate's lockdown decree and come to China as a smuggling ship without authorization, and did everything possible to infiltrate the Jin merchants' convoy and really go to the battlefield to have a look.

After that, he was deeply touched, and after studying in China for five years, he really wanted to enter the military academy, but there was no channel, so he tried his best to get a set of military textbooks from the military academy students, and then while working, he studied on his own, and went to the school to observe the market, and through self-study, he figured out the principles of the modern military system.

When he returned to Japan, he was initially treated as a samurai by the Choshu Domain, but when the Clansmen learned of what he had learned, they recommended him to the feudal lord, who asked him to establish a school and began to popularize modern military science in Nagasu. A few years later, he trained a group of officers, and with these officers as the backbone, on the advice of Yoshida Shoin, the Choshu domain established the Odd Soldiers, recruiting ronins and peasants as soldiers, and became a non-samurai army.

The Choshu clan also managed the army through junior samurai who had served in the Chinese army, and the number of senior and senior officers in the army was reasonable, and as a result, the Choshu army stood out from the crowd and won every battle.

When the decisive battle of Bichu began, the Choshu coalition had only 80,000 troops and the shogunate army was as high as 120,000, and as a result, the Choshu domain once again defeated the shogunate army and advanced its sphere of influence to Himeji Castle.

At this time, the War of the Shogunate of Japan evolved towards a new Warring States War, and if it continued to develop, it was possible that the Mori family would replace the Tokugawa family and establish a new shogunate.

The Choshu Domain had already built some military factories of its own, and the British produced weapons and equipment in India, and they had their own only military school in Japan, and their advantages over the shogunate became more and more obvious. Daimyo from all over Japan began to take sides, knowing that victory or defeat would determine their family's honor and disgrace for hundreds of years to come.

The biggest trouble of the shogunate is not that it is inferior to each other in terms of manpower and material resources, but because of political decay, as the current regime, all social discontent is concentrated in the shogunate, and hundreds of thousands of poor samurai blame their plight on the shogunate's rule, regardless of whether the Maori family can change their future or not, but at least it is a possibility. As a result, the lower-ranking samurai took refuge in the Maori family, replenishing the Maori family with a steady stream of soldiers.

The shogunate's military system was severely backward, and it was unable to organize its military resources without huge manpower and material resources, and it also had to face continuous rebellions in the territory, and successive defeats caused the peasants and citizens to revolt.

China, the shogunate's backer, was playing parliamentary, and the crown prince was not interested in telegraphing to the shogunate once a week. The only thing the shogunate could rely on was the Chinese consul, who reported the situation to the country, and the country could not make up its mind for a while. Let the consul try to mediate as much as possible.

The face of the Chinese consul was still to be given by the upside down faction, and Maori Jingqin met with the consul in person and put forward some requirements. Mori did not ask the shogunate to step down, but he demanded that the public and military forces be united, and that the powerful feudal clans should participate in the politics of the shogunate, and that the powerful feudal clans take turns sending personnel to hold important positions in the shogunate. Moreover, it is necessary to ensure that the territories they have already seized and that the vassal states have absolute power in the management of the territories, including mines, ports, and customs duties, are all under the management of the vassal states.

The shogunate rejected these demands, which amounted to hollowing out the shogunate and allowing the powerful feudal clan to control the shogunate.

War broke out again, and this time the Tohoku Empire finally joined in, first expelling the shogunate officials from their own domains, taking control of their country's mines and ports, and then openly expressing their stance and joining the shogunate faction.

The shogunate began to face a two-front war.