vintage Arita blue & red Japanese porcelain chargers or platter plates, Japan label & chop mark

Two large Japanese china plates or chargers with different birds, both 12" in diameter overall. They're not antique, but mid to late 20th century as you can see from the Japan label.

We've been told that these are typical pieces and patterns for 20th century Arita ware, but aside from that, know next to nothing about these. And we haven't been able to translate the characters of the mark. Both of them are in very nice condition without damage.