Momo

Momo, officially Honma Momo, is a potential companion and daughter of Lord Honma, the lord and player's potential deputy of Sado. To gain her as a companion, you must speak to her after claiming Sado and then ask Lord Honma for permission to take her.

She is of noble birth so shouldn't cause any relation loss upon being granted a fief.

She is a blank slate companion, she can be trained in any way the player sees fit.