Japan, China, South Korea, North Korea, Vietnam, Laos.
Diffusion from Korea and China
Japan was already seperated from China from the start, and Korea became seperated from mainland China by Japanese influence expanding in Korea after Sino-Japanese war in 1895.
China
The chinese defeated the area called Manchuria or Korea, so for a while, Korea was a part of Chinese land holdings. Japan was never part of China.
passing cultural ideas from China to Japan
Yes, it was. Buddhism spread From India to China then to Japan, the Koreas, Tibet (part of China) and Vietnam.
it spread the religion of budhism to china which was spread to Korea and then japan
It first spread to China and Sri Lanka. From China it spread to Tibet, Japan and Korea. From Sri Lanka it spread to the rest of South East Asia.
The neighboring countries of North Korea are South Korea, China, Russia, Japan, and Mongolia.
Acting as a bridge for ideas from china
Han Wudi when he invaded Korea and Vietnam in 124 BCE.
china and korea
Japan fought against China and Korea.
china and korea
China and North Korea have poorer economy compare to South Korea and Japan.
Japan is closer to Korea than China. The distance between Japan and Korea is about 210 kilometers (130 miles) across the Korea Strait, while the distance between Japan and China is around 1000 kilometers (620 miles) across the East China Sea.