Tatsumiya is an oarfish that has served the court since the time of the original Sea King. She is Wadanohara's foster mother and was Meikai's familiar. Tatsumiya speaks in an intelligent manner, and has been shown to be very caring. She cares deeply about Wadanohara due to the bond she shared with Wadanohara's father, and as such Tatsumiya frequently worries about Wadanohara's well-being. She is almost always calm, but there have been exceptions to this when she is faced with trouble.