"Of course I understand, Cocytus. However do you not want Momonga-sama to leave an heir behind for us to pledge loyalty to?" An image of Momonga's heir floated into the head of Cocytus. Not only that, teaching him swordsmanship in order to protect himself, listening to the orders of a grown up young master. From Volume 1.

"Hello, Father," she said. "I have returned. Tell Mother."