Antique Japanese large plates and large bowl

My husband's father gave us these for free today. I have looked online endlessly for at least 5+ hours. I would like to know what they are, where and when produced, and the price. I collect blue and white dishes. I want to know so I can display appropriately. They are quite heavy. They have tiny brown specks in the material. I don't know what that means. It is not dirty. It is all over in the actual material it's made of. The signature on the bottom is hard to read. I couldn't find a match for them either. Also it is accompanied by a made in Japan sticker. The plates measure 10 inches, the side depth is about an inch. Like large saucer or salad plate. The bowl measures 10 inches, the depth is 2 1/2 to 3 inches. The finish is not smooth. Appears hand glazed. Any help would be appreciated. Thank you so very much in advance for any info.

Excellent