Examples of brushes from the eighth century CE (corresponding to the Tang Dynasty, in China) are preserved in the Shōsōin, in Japan; in fact, the prestige value of this type of bamboo was evidently so high at the time that among the Shōsōin treasures are preserved objects made out of some sort of imitation spotted bamboo.
The name, Yamagata, has already existed in one of the oldest Japanese family registry which was published in 702 and has been stored in Shosoin, Nara.