Wow, really nice mirrored pair. I wouldn’t have known what these are either. Bit of a cross between Kutani and maybe Kyoto....but Mikawachi, as JRN has identified. Question: I can’t figure out what the handles are. Snails? Or is it a beast with a long tongue? 

Todd

While these definitely favour Kutani in looks often or is sold as such: it’s actually Mikawachi-ware (where Hirado was produced priorly). 

Reads “Hichozan Shinpo Zo”

Hichozan was a finishing shoppe/brand for the exporter merchant Tashiro Monzaemon.
Before the time of Meiji, he was one of two merchants in the area allowed to trade in exports under the domain. 

Later Edo period/very early Meiji, mid-19th century.
Hope this helps.

Best,
-JRN