Mepoco Ware Made in China

This china set has been in the family for as long as I can remember but I have no idea how it came into the family or where it came from. I know my uncle was in Japan during WWII and have a feeling he brought it home as a gift to my mother. On the back is stamped Mepoco Ware Made In Japan inside of a flag. At the top of the short flagpole is a small circle with an H inside of it.

Anyone know anything about its history?