In 1866, the Choshu han (Choshu feudal clan) had talks in Kyoto with Saigo Takamori from the Satsuma han, through the mediation of the two important figures, Sakamoto Ryoma and Kido Takayoshi, and as a result entered into an alliance with the Satsuma han. Around the time when Takasugi Shinsaku assumed the helm of the Choshu han, their purpose changed from protecting Nippon from foreign invaders to bringing down the Bakufu. The Bakufu tried to subdue them, however, it was the Choshu han that won a landslide victory. After calling for a truce, the new Shogun, Tokugawa Yoshinobu, established bureaus for domestic affairs, foreign affairs, accounting, army and navy, on the advice of L. Roches, French Ambassador. He also implemented a variety of reforms. Meanwhile, the Choshu han enhanced their military power with the assistance of Sir. H.S. Parkes, British Ambassador. Having noticed this move, the Bakufu decided to return political power to the Emperor. This was a trick to save the Bakufu.
However, Satsuma and Choshu remained determined to bring down the Bakufu. They asked the Emperor to declare the Restoration of Imperial Rule. After all, the Bakufu's attempt to take a leadership in the new government ended in failure. This was the time when Nippon entered a new era where the Emperor was the nation's actual leader. Shogun Tokugawa Yoshinobu was born and raised in the pro-imperial Mito han, where people instilled unquestioning obedience to the Emperor in him. The country escaped the crisis thanks to this. Katsu Kaishu, the Bakufu's Naval Commissioner had talks with Saigo Takamori, de facto Officer in Command of the new government, and as a result, the Edo Castle was surrendered to the new government without bloodshed. This story shows what the genuine samurai was. The last Shogun Tokugawa Yoshinobu, who saved Nippon from colonization at the cost of his own status, really embodied the Bushido (the code of the samurai.) Later on, the privileged warrior class also abolished the feudal cast system on their own initiative under the Meiji government.
Asia is an incredibly wide area, including West Asia and East Asia. The Industrial Revolution fuelled imperialism in Europe and as a result, just about all the Asian countries were colonized. As far as I know, the only exceptions were Nippon, the Kingdom of Thailand and the Kingdom of Nepal. If one wants to protect his country, one needs to be ready to risk his own life, which is the most important right each individual has.