This plate is of exceptional quality. Each face is a realistic portrait. It is 8-3/8" in diameter. The edge has an interesting "crimp" in 5 places.
My friend Shigeko translated the signature for me. It is signed Takeuchi below the Shimazu circular family crest.
The condition is excellent: no chips, no cracks, no repairs, no wear. It is marked on the back as shown in the last photo.