In June 1853, Commodore Matthew Perry of the United States Navy led a squadron of four heavily armed warships into Sagami Bay, to the Port of Uraga, just south of the shogun's capital at Edo. What the Americans found was a technologically backward, though intricately complicated, island nation, under the rule of the House of Tokugawa, that had been isolated from the rest of the world for two and a half centuries.

Whether or not the Americans realized the far-reaching effects of their gunboat diplomacy, they now set into motion a coup de theatre which fifteen years hence would transform the conglomerate of some 260 feudal domains into a single, unified country. When the fifteenth and last shogun, Yoshinobu Tokugawa, abdicated his rule and restored the emperor to his ancient seat of power in November 1867, Japan was well on its way to becoming an
industrialized nation, rapidly modernizing and Westernizing in a unique Japanese sense.

Quite a transformation in just fifteen years, and much of the credit goes to a lower ranking samurai from the Tosa domain named Sakamoto Ryoma. When Ryoma fled his native Tosa in spring 1862, he was a "nobody." Although he was a renowned swordsman who had served as head of an elite fencing academy in Edo, and was also a leader of the young samurai in Tosa who advocated the radical slogans Expelling the Barbarians, Imperial Reverence and Toppling the Shogunate, in the eyes of the power that were he was a "nobody." He had never held an official post, and he never would. When in the following October the "nobody" met Katsu Kaishu, the enlightened commissioners of the shogun's navy, it might have been with intent to assassinate him. But, of course, Ryoma did not kill Kaishu. Instead, this champion of samurai who would overthrow the shogunate and expel the barbarians became the devoted follower of the elite shogunal official. Kaishu opened Ryoma's eyes to the futility of trying to defend against a foreign onslaught without first developing a powerful navy; and to this end Japan desperately needed Western technology and expertise.

Ryoma now worked with Kaishu, whom he called "the greatest man in Japan," to establish a naval academy in Kobe, where he and his comrades studied the naval arts and sciences under their revered mentor. But certain of his hotheaded comrades called Ryoma a turncoat for siding with the enemy, which, of course, was not true. As if to belie the false accusation, in the following June Ryoma vowed, in a letter to his sister, to "clean up Japan once and for all." What he was talking about was overthrowing the military government, which Kaishu loyally served. Earlier in the same month, ships of the United States and France had shelled the radical Choshu domain in retaliation for Choshu's having recently fired upon foreign ships passing through Shimonoseki Strait. News of the attack deeply troubled Ryoma, who was concerned about possible designs among the Western powers, particularly France and England, to colonize Japan as the latter had China. When Ryoma learned that the foreign ships that had bombarded Choshu were subsequently repaired at a Tokugawa shipyard in Edo, he was fighting mad. "It is really too bad that Choshu started a war last month by shelling foreign ships," he wrote his sister. "This does not benefit Japan at all. But what really disgusts me is that the ships they shot up in Choshu are being repaired at Edo, and when they're fixed will head right back to Choshu to fight again. This is all because corrupt officials in Edo are in league with the barbarians." But, now, through the good offices of Katsu Kaishu, Ryoma too was in league with some very powerful men. "Although those corrupt shogunal officials have a great deal of power now, I'm going to get the help of two or three daimyo and enlist likeminded men so we can start thinking more about the good of Japan, and not only the Imperial Court. Then, I'll get together with my friends in Edo (you know, Tokugawa retainers, daimyo and so on) to go after those wicked officials and cut them down."