According to the clothing code in the Yoro Ritsuryo Code, Chofuku were worn to attend the government meeting called 'Chokai' that was held once a month in a open court and when the court nobles does things called 'Kuji.'
養老律令の衣服令によると、朝服は、毎月一回、当時朝庭と呼ばれた場所で朝会と呼ばれるまつりごとをするときと、当時公事と呼ばれたことを行なうときに着る服である。