Сумако Аоцуки

Усио's mother, who mysteriously vanished when he was still an infant, is in fact the third Oyakume. For several centuries, she has been holding a seal deep in the ocean to protect the Shiroi-likko, as it would immediately destroy the Japanese archipelago if attacked by any yokai or human. This is why the other yokai despise Sumako. Jiemei allowed her to rest for a few years, during which time she met Shigure and gave birth to their son, Usio.