Satchō Alliance (薩長同盟, Satchō dōmei), alternatively called the Satchō Contract or Satchō Union, refers to an agreement made during the end of the Tokugawa regime between two anti-shogunate parties from two feudal domains, Satsuma and Chōshu. In an age where daimyou were raised within the confines of dusted antiquity, it was the lower class samurai, drenched in the thick of the era, who held influence in either domain.
Satsuma, a once giant domain in Kyushu, had the daimyou's family married into the Tokugawa family so they were officially supporting the shogunate. The domain's leaders did not reflect the will of a prominent and influential resident samurai, Saigō Takamori. After the daimyou's disappointing display of leadership in the Namamugi Incident and Anglo-Satsuma War, Saigō threw in his lot with anti-shogunate parties and joined forces with local samurai nobles Komatsu Tatewaki and Ōkubo Toshimichi, welcoming an alliance with foreign parties through his contacts with Harry Parkes. The domain enjoyed wealth and healthy trade as exclusionists.
Chōshu, west of the capital in modern day Yamaguchi Prefecture, became a cornerstone for the military extremist movement. It was home to the samurai scholar Yoshida Shōin, who famously taught and inspired several other samurai such as Katsura Kogorō, Takasugi Shinsaku, and Kusaka Genzui. When the shogunate made the controversial move to dissolve local authority in two of its major cities (Yamaguchi and Hagi), a vocal minority of the samurai within Chōshu decided to revolt. With skilled negotiations and discreet support from neighboring sympathizers, their numbers grew to an alarming rate.
It is popularly believed that Sakamoto Ryōma and Nakaoka Shintarō were responsible for uniting the two groups by overseeing and arranging the negotiations. Both sides either agreed to topple the shogunate or overthrow the Ichijo branch of the Tokugawa family. Historians are currently arguing that it could have been one of many under-the-table agreements which has been given exaggerated importance due to folklore and fiction.
Regardless, the pact was an agreement for either side to provide military arms. Satsuma supplied the Chōshu forces with upgraded firearms and the means to withstand the shogunate forces in 1866. The alliance is known to have lasted until the Meiji period.
In the GamesEdit
Koei games favor the romanticized portrayal of the union by having Ryōma at the forefront of mediations. Proponents for the Ryōma perspective states that he created a six-point contract of friendship for both parties, but there are no surviving records which can verify its existence.
The Ishin no Arashi series includes the alliance as a special historical event in every game. Reenactments require Ryōma, Shintarō, Takamori and Kogorō to still be alive in 1865 and banded under the anti-shogunate policy of the game. Historical routes are modified to curve naturally towards these settings. Choosing to raise a pro-shogunate protagonist often negates the alliance from their adventure.
Harukanaru Toki no Naka de 5 includes the alliance as a major story event. If successful, it unifies the rebel parties and the spiritual bonds between the Eight Guardians, weakening Amami's influences beyond the capital.