Otohime
She is the witch of the deep who started to work in a fishing goods store namely “Bait & Tackle Period” after her popular underwater business “ Ryuuguujou Castle” had closed down. She blames the mermaids, particularly Muromi and her associates, for spreading false rumors which results in her business failing.
She has an Oarfish who once serve as her familiar, who, is the unfortunate one to be on the receiving end of his mood fits.