In one of the most pivotal moments in Japanese history, fifteen-year-old Emperor Mutsuhito was discovered dead in his chambers. His father had died from illness (arguably caused by poisoning) just over eleven months earlier, and now the country fell into civil war as the imperial court attempted to edge out the old guard. Many historians conclude that the assassination promoted war as each side blamed the other for the unsolved death.
A coup from the rebelling south in Satsuma and Choshu surrounded the emperor and gained great influence. They orchestrated an order in the emperor's name to call for the execution of Yoshinobu, who resigned in a ceremony of stripping him of land and titles despite his having performed no crime. He fell into retirement as according to the emperor's wishes, but Mutsuhito would be assassinated some weeks later. Yoshinobu was blamed and demands of his life were sent by the southerners. He refused to comply with the imperial court, whose coup he saw now as clearly murderous, and he sent forces southward. The Tokugawa armies, though improved by French advisers, were still largely samurai while the imperial army at Edo was modernized while outnumbered three to one.
The war followed samurai gains, which spread anti-foreigner sentiment around the islands. On March 8, at Sakai near Osaka, eleven French sailors were killed, which prompted the French ambassadors to send for help from Indochina, where the French were currently warring with rebels to maintain peace. French naval ships and troops arrived, coming to aid the imperial court. A puppet emperor was installed, and the French pushed samurai forces back, stomping out pockets of resistance over the next year, which also enabled them to gain footholds militarily over the islands. Japan was named a French colony in June of 1870, mere weeks before the disastrous Franco-Prussian War began.
The Japanese would prove stubborn subjects, and the French routinely sent new expeditions over the course of the Third Republic to put down uprisings, most notably the push for an end to Western rule in 1904, mirroring the struggles America had with its colony in the Philippines to the south. France and the United States would share resources to bolster their western Pacific colonies until World War I, when attention would turn to Europe. Russia's grossly outdated army would collapse almost immediately under German invasion, a quick end on the eastern front in sharp contrast to the dragging trench warfare of the west. After the war and the economic collapse following rebuilding of Europe, communism arose as a new strategy for society. Coming out of China, Japan would be fertile soil for communism after years of objecting to the hierarchy imposed by westerners. With the fall of France to the Third Reich, Japan and Indochina would undergo revolutions, then channeling supplies to China and Russia for their own civil wars.
Communism took firm root in the Far East, spreading to other nations previously under colonial control. It met stiff resistance from the West, and the two worlds would battle economically and militarily for decades through the twentieth century.
In reality, Emperor Meiji announced his restoration to supreme authority and, after a brief resistance by Yoshinobu and the samurai, began a new era of reforms. Their economic influence and military prestige would become obvious in their defeat of a western nation in the Russo-Japanese War in 1905. Japan continued its growth of political clout as it joined Hitler's Axis, prompting the Pacific theater of World War II. After suffering the only military use of atomic weapons, Japan would rebuild to become an economic world leader.