Reading for 美峰 is probably bihou, likely the name of the shop that made it. Found some other porcelain ware from shops with that name when I searched it.

I don’t know Japanese but I do know Chinese. The red characters, upside down, should be 美峰, and the sticker, right side up, should be 宮

The one on the sticker is normally written as 宮 (miya - big shrine, palace). There is a way of writing Kanji that makes them even boxier than the standard ones, often for use in stamps that painters use to sign their work. This looks like a stylised version of that with a thicker brush stroke where they just extended the little vertical lines downward. For fun.

The hand painted ones are upside down. No clear idea how to read them honestly because the combination doesn’t appear to be used much or is a place that is famous enough. 美 (maybe mi - beautiful, august) 峰 (probably mine - mountain ridge). Could be a place or a quote from a haiku where shit gets condensed like a tweet or something.

The bottom character kinda looks like it might be a fancy 美 (beauty), but I’m not sure. I have no idea what’s going on with that top one. I can’t figure out what the radical on the right is trying to be.

Man, it’s weird that in both languages I’m familiar with the ‘fancy’ script is nearly illegible chicken scratch. Why does that keep happening? Maybe a way to appear appease certain nobility that couldn’t write for shit?