3C: Ancient times
The combined thing of Chinese Koto and Japanese Koto blossomed in the concerts at the Court
By the research, Koto was seen as the sacred tool which was used by influential and powerful people. In the 8C, Nara-era, Chinese Koto came to Japan with musical grammar and both Chinese and Japanese Kotos were combined and diversified.
In Heian-era Koto became one of cultures/educations and nobles were expected to be familiar with it. Later, the reform happened and complicated music theories and instruments were organized into Japanese style. The instruments based on Chinese and Japanese Kotos were categorized into Sou, Wagon, and Biwa (all of them are the names of different kind of instruments). In “The Tale of Genji”, those instruments were represented. It was a time that Japanese culture bloomed like Kana-literature, and Koto were familiarized among the upper-class women who served with the Court.