What is the origin of Japanese and Korean traditional musical instruments with China?

Of course they originated in China! What else is there to ask? If there is any difference, it is also a slight modification of the Chinese instruments! The Japanese koto! It's basically a Chinese koto... I think it's because they didn't get it right when they copied it, so they couldn't call it a guzheng, but they didn't want to give it up, so they called it a guqin. Besides, it's written in the ancient books! They all came to China to study.