Tatsumiya was Meikai's familiar and the one Meikai had chosen to wield the Sacred Sword. She remained as his familiar up until his supposed death.

Moments prior to his death, Meikai entrusted the care of his daughter Wadanohara to Tatsumiya. Respecting her master's wishes, Tatsumiya filled the role of parent for Wadanohara in place of her absent father and mother. It was her who taught Wadanohara all of the magic she knows, Tatsumiya passing down to Wadanohara the magic her father used.