Why is Japanese classical light music so similar to China's? What is the origin of the two?

It was during the Sui and Tang Dynasties in China that Japan was transformed into a new country. China was the most powerful country in the world at that time, while Japan was just a small slave country. Japanese people have a strong learning ability. In addition to music, Japan has also studied China's political system, fine arts, costumes, writing and so on, so Japanese culture can be said to be a branch of a story with China. But because Japan itself is developing, cultural differences are inevitable, so you can hear similarities but not similarities.