And later in Tang Dynasty, the weight standard of 'kin' and 'ryo' was reduced and Kaigen Tsuho ('Kai Yuan Tong Bao' in pinyin, a coin of the Tang Dynasty China) was minted at the weight of a 10th of 1 ryo which was equivalent to 10 sen (or 10 monme).
後の唐代に「斤」、「両」の質量が縮小し、開元通宝が1/10両の基準で鋳造されたため、10銭（匁）と等しいとされるようになった。