Rakuzan ware (楽山焼 (愛媛県), Rakuzan-yaki) is a type of Japanese pottery traditionally made in Matsuyama, Ehime prefecture.
A little red-clawed crab (赤手蟹 akategani) peeking out of the sides of the vessel is the trademark.
References
Rakuzan ware (Ehime) Wikipedia(Text) CC BY-SA