Write a realistic, sensible, plausible and alternate history scenario in the form of a historical documentary book chapter set in the world of the alternate historical scenario with no references to this being an alternate history scenario or to the real world timeline at all, in which  the Imjin Wars of May 23, 1592 – December 16, 1598 launched by the Ashikaga shogunate de-facto lead by Toyotomi Hideyoshi-ruled feudal Japan against the satelite state and tributary kingdom of Great Joeson ruled by the partially Han Chinese Korean House of Jeonju Yi in Korea and the  Han Chinese Imperial House of Zhu-ruled Ming dynasty ruling over both Han China and Cantonia end in a victory for feudal Japan, with Joeson being dissolved and the Korean peninsula being absorbed into Japan as the newest Japanese province and the Ming dynasty essentially becoming a Japanese satellite state in the peace treaty signed in the feudal Japanese capital of Kyoto, with Hideyoshi taking the last King of Joeson before the Imjin War's Seonjo's daughter, Princess Jeongmyeong as his [Hideyoshi's] latest concubine. The position of King of Korea still exists and Korea is a kingdom de-jure, but the Japanese revive the pre-Joeson Goryeo Kingdom as the local governance of post-Joeson Korea as a Japanese province. In the aftermath of the victory over the Ming and the absorption of the Korean peninsula into Japan, the Japanese Imperial Family, the Imperial House of Great Yamato/Minamoto dynasty, decides to use this opportunity to reclaim the power it [the Imperial House of Great Yamato/Minamoto dynasty] has [the Imperial House of Great Yamato/Minamoto dynasty]  lost to the shoguns and the samurai class over the years and [ the Imperial House of Great Yamato/Minamoto dynasty] regaining executive control of the Japanese government, essentially making Hideyoshi's roles of Chief Advisor to the Emperor and Chancellor of the Realm into a position akin to the Prime Minister in Western European countries or the Reichkanzler in the Germanic lands while using the excuse of purging the newly claimed Korea of pro-Chinese Confucianist and neo-Confucianist elements, native Korean shamanism as well as the power of Korea's native aristocracy, the yangaban as well as freeing the mostly enslaved Korean population and making the Korean commoners long oppressed by both the yangaban and the  House of Jeonju Yi into Japanese citizens during the integration of post-Joeson Korea into feudal Japan as a means of restoring the imperial system of government in Japan before the establishment of the feudal shogunates in a modern context, although the basic governmental style and social structures of the shogunate remain unchanged. Hideyoshi then replaces Confucianism and neo-Confucianism along with native Korean shamanism in post-Joeson Korea, with the Japanese state religion of Shinto, Buddhism and even Christianity, which mostly succeeds as the yangaban have been replaced with Japanese daimyō [feudal lord/s during Japan's feudal period under the shogunates |daimyō|] and the rediscovery of the native Korean Hangul script for writing the Korean language by the Japanese and its [Hangul's] promotion by the Japanese as the way of writing Korean over the Chinese script known as Hanja used by the now-deposed Joseon royal family and the Yangaban for writing in Korean with Nihongo [the Japanese language/Japanese |Nihongo|] and Kanji [the Chinese characters used to write Nihongo |Kanji|] also being promoted in post-Joeson Japanese Korea. 

By the time Hideyoshi dies on  September 18, 1598, with his [Hideyoshi's] nephew Toyotomi Hidetsugu succeeding him [Hideyoshi] as both Chief Advisor to the Emperor and Chancellor of the Realm and his [Hideyoshi's] young son Toyotomi Hideyori next in line to succeed both Hideyoshi and Hidetsugu as Chief Advisor to the Emperor and Chancellor of the Realm, with the then-reigning Emperor Go-Yōzei using this as an excuse not to appoint another shogun until Tokugawa Ieyasu attempts to take control of Japan from Hidetsugu and nearly reopens the Sengoku period.  Go-Yōzei then appoints Ieyasu as shogun on March 24, 1603, causing the start of the Tokugawa shogunate and forces Ieyasu not to break the arranged marriage between Hideyori and Ieyasu's granddaughter Senhime, with the intention of making their [Hideyori's and Senhime's] first male child into the next shogun after Ieyasu's son Tokugawa Hidetada and also with the intention of uniting the Toyotomis and Tokugawas into a single family, securing the line of shogunal succession while ensuring that actual power in the Japanese government remains within the Imperial House of Great Yamato/Minamoto dynasty. 

While this is going on Japan continues to improve and develop its [Japan's] firearms and artillery technology, [Japan] also continuing to improve its [Japan's] naval might while [Japan] solidifying the Ming dynasty's status as an unofficial Japanese vassal and satellite state in a reversal of the usual relationships between China and Japan through joint military exercises, suppression of bandits and would-be usurpers in Cantonia and the deportation of yangaban and Sinophilic House of Jeonju Yi members to Ming-controlled Han China

The Tokugawa shogunate still maintains its position of isolation from the rest of the world, although this is challenged by the rise of the Jurchen tribes from Manchuria and Outer Manchuria and their subsequent conquest of China. The Japanese initially support the Ming in the fight against the Jurchens but realize that the conflict will eliminate anti-Japanese elements in China and so allow the Japanese to maintain power in East Asia. 

The Jurchens conquer much of northern China and even parts of Central China, establishing the Great Qing Empire while the rump state of the Ming becomes the Southern Ming, still under Japanese protection. The half-Japanese Zheng Sen, better known as Koxinga, still establishes the Ming satelite state/rump kingdom of the Kingdom of Tungning on March 30, 1661 – February 1, 1662 in Taiwan and the Pengu Islands, but since his [Koxinga's] mother, Princess Minamoto Matsu aka Tagawa Matsu is closer to her [Matsu's] family [Imperial House of Great Yamato/Minamoto dynasty], the Kingdom of Tungning is a Japanese puppet state in all but name. 

Negotiations with the Qing end the conflict and so East Asia enters a new Three Kingdoms period: The Qing based in Manchuria and Outer Manchuria, the Ming in Han China and the Japanese ruling over the Japanese Home Islands, Korea, Taiwan and Okinawa.

The Southern Ming conquers Indochina, using the opportunity to absorb the Vietnamese into the Han people