How was japan able to avoid being a victim of western imperialism?

At the start of the 19th century, Asian countries had militaries less effective than Western nations.

In 1853, the US Navy forced Japan to enter into trade with the United States. The Japanese realized they were too weak to defend themselves then and had to agree to the terms. Thereafter, the Japanese started to modernize themselves and became a major Asian power in the 20th century.

China had its own humiliating experience that should have jolted it into similar action like Japan. It was the first Opium War with the British. It occurred even earlier in 1839 and was far more unjust and humiliating. China suffered another major humiliation at the hands of the Western powers during the Boxer Rebellion. Unfortunately, China did not modernize and remained weak throughout most of the 20th century.