The origin of the Japanese 'chofuku' is "Shanfu" (everyday court dress) in Tang ('chofuku' in Tang was a different thing of the same name), and the robe of this Shanfu derived from Kohuku (traditional clothes for Kojin [who lived in Northern China in ancient times]) (according to "Meng Xi Bi Tan" (Dream Stream Essays)).
日本の「朝服」の祖形になったのは唐の「常服」であるが（唐の「朝服」とは同名異物）、この常服のうわぎは胡服の系統を引くものであった（夢渓筆談ほか）。