In the age of the Sung Dynasty, 10 to was set to be 1 koku (石), and 5 to was set to be 1 koku (斛), and ever since the koku (石) and koku (斛) are different unit in China.
宋(王朝)代に10斗が1石、5斗が1斛と定められ、以降、中国において石と斛は別の単位となった（zh斛）。