The grass-shaved sword still preserved in Japan is regarded as a national treasure by the Japanese. In Japan, it not only has the value of cultural relics, but also is regarded as sacred or sacred. Formerly known as "Heaven from the Cloud". The Japanese Book of Records also records the story of the grass-shaved sword showing its spirit. Among the three treasures used as a token (equivalent to a jade seal) when the Japanese emperor acceded to the throne, there was Yun Jian, a genius-of course, as the author of Chrysanthemum and Knife said, the original sword had sunk to the bottom of the sea in a turmoil, and now the royal family only uses imitations.