Even though the Japanese civilization was probably later than the Chinese civilization, much less is known about early Japanese history as it is often morphed with myth and legend. In the 19th century, Japan and China had a strong rivalry. While China was under European influence, Japan was a much more closed country, though it did westernize over time.
In the 1920s, Japan became fascist and this new government was led by a man named Hideki Tojo. Over the course of the 30s and early 40s, Japan seized large sums of territory including Korea, parts of China, Malaysia, Thailand, French Indochina, Philippines, and Indonesia. As a result, the US implemented an oil embargo which provoked the Japanese into the pearl harbor attack. The main difference from this timeline and OTL is that Great Britain and France also waged war against Japan due to the lack of war in Europe. As a result, the war ends in late 1944.
The European powers forced massive reparations on Japan and executed both Tojo and emperor Hirohito. From 1945-1959, there was the Japanese republic. This period ended when a former veteran, Fuchi Kazuki, was elected prime minister and began a transition into fascism. He promised the Japanese people a return to its former glory. There was hardly any outcry from the locals when Kazuki centralized power because the Japanese people were anti-American and anti-Entente. As a result, Japan found an alliance among Germany, Austro-Hungary, and Italy. In addition to the abolition of western ideals, Christianity was also outlawed. Because of Kazuki's militaristic nature, the flag of Japan was changed to the former military flag. Over the course of the 60s, Japan made numerous territorial gains including British colonies. This would normally lead to a European war but the threat of mutual assured destruction prevailed, limiting British involvement.
|Flag of Fascist Japan|
Flag of Fascist Japan
When the second pacific war broke out, Germany was unable to interfere due to the Balkan war. in 1975, Operation Samurai, an operation to quickly take the United States, was carried out. The northwestern US was quickly taken by the Japanese as well as California, Hawaii, and parts of Alaska. However, they were unable to take Colorado due to the Rockies and never went into the southwest in order to quickly march into DC. So their army advanced through the great plains and had plenty of food to eat but the American campaign ground to a halt when America drafted enough individuals to drive back Japan. Since America's planes were far superior to Japanese planes, the Great Plains heavily exposed the Japanese forces. By 1978, Japan was on its last legs as most of its army had been devastated, its territories began revolting and the country was too out of shape to crack them down, and the mainland was now exposed to the US. Two cities were destroyed, Hiroshima and Nagasaki by atomic bombs. After the destruction of Nagasaki, Fuchi Kazuki refused to surrender to American forces but the demoralized Japanese military overthrew him in a coup and the country surrendered.
In the aftermath, Fuchi Kazuki was put on trial and executed. The Kennedy administration was far more merciful than the Roosevelt administration; reparations were not sought and the massacres carried out by the Japanese were associated with Kazuki rather than with the Japanese people. The US assisted Japan in rebuilding as well as China
Japan has a strong economy though not as strong as in OTL. Japan is close allies with china and the US and is among the founding members of the North Pacific Treaty Organization (NPTO). The country's population is aging and its economy is slowing down. China is the economic powerhouse of Asia, not Japan. Japan's media watchdogs are just as regulatory of media as OTL Germany. All nationalist parties advocating a return to the 60s era are banned, the rising sun is banned, and the media watchdogs are heavily regulatory of violence and discrimination in movies and video games leading to quite a few mature games being banned in the country. This has had an effect on China, the birthplace of anime which has often had to tone down its violence for Japanese media. However, they don't censor sexual content as heavily as western media.