What existed in the center of Tenka was the area which the Chinese dynasty directly ruled, and it was called "Ka", "Ka", "Chuka", "Chuka", or "Chugoku" etc.
天下の中心にあるのが中国王朝の直接支配する地域で、「夏」「華」「中夏」「中華」「中国」などと呼ばれる。