Wadanohara and the Great Blue Sea

Wadanohara and the Great Blue Sea manga summary: The beautiful blue sky, the vast blue sea. A tiny boat in crystal clear ocean. The sea witch Wadanohara, along with her familiars, is returning to her underwater hometown after a long time away. But before her looms her first familiar, Samekichi. "You... Get away from this sea right now. You should not be here..."