Zen Buddhism is essentially Chinese. It evolved from Chan Buddhism which was a hyrid of Taoism and Buddhism that was primarily Taioist. Chan buddhism originated in China and then moved to Japan after hundreds of years developing on mainland China. Zen Buddhism is just Chan buddhism translated into Japenese. It's not a Japanese creation, it's a Chinese creation.

Because the Japanese are so racist and xenophobic, they would not acknowledge that Chan buddhism was essentially the same ideas as Chan Buddhism just translated into Japanese. When Japan was strong militarily, the Zen Buddhists murdered all the other Chan buddhists on mainland China and Chan buddhism dissappeared.

Essentially the Japanese wanted to take credit for Zen/Chan and to do so they decided they needed to murder all the other Chan buddhists who they looked down upon because they were Chinese and not Japanese. They wanted to make Zen/Chan a Japanese possession so they murdered off the Chan buddhists - women, children, priests, everyone.

It was a massive genocide on mainland China that's disappeared to history. History is much more obscure in the east. The Chinese government covers up and distorts its own history. The Japanese lie about their history. A lot of religious and historical texts were burned in Asia.

The Japanese and the Chinese both burned a lot of historical records. Paper was invented in China, so paper was what was used for records, religious texts, business use, etc. Unlike in the West where they carved a lot of things into rocks so that historical lies couldn't be told, in the east it was all paper that was burned. Large swathes of Chinese and Japanese history have disappeared because all the historical records were burned.

The Genocide of Chan Buddhists was one of those lost episodes of history. The Japanese Empire also is not talked about because the Japanese are embarassed that they once had an empire on China and then had to retreat back to Japan. The motivation for Japan in WWII to occupy China and Korea was an attempt to recreate their long lost empire they don't like to talk about to non Japanese.

The Taoists used to write in obscure symbolically laden poems that were painted with brushes on silk scrolls. Along with the poems they would paint beautiful scenes of the natural world. The reason they made metaphoric poems was that they knew that if they spoke directly, their words would be burned. They painted beautiful paintings next to the poems thinking that people wouldn't burn a beautiful painting. That's how a Taoist thinks, they tried to prevent the loss of knowledge by creating something beautiful that no one would want to burn.