The Romans had connections with ships from Aqaba that went to India for (black) pepper, so it's possible, but it would have gone through many hands as you suggest; it would be easier to simply have one trader take it all the way to Xian, and another from there to Nara.
What interests me is how similar in style and shape this is to Song dynasty wide-and-flat bowls, which eventually become the basis for hirajawan used for drinking tea in Japan in the summer.
My understanding is that most of the traffic on the the Silk Road also went thru many intermediaries. Traders running a single load the whole distance of the Road were probably the exception if they existed at all.