Nayuta (ナユタ) is the reincarnation of the Control Devil (支し配はいの悪あく魔ま Shihai no Akuma) following Makima's death. To prevent her from becoming similar to her previous incarnation, she was taken by Kishibe to be raised by you as your younger sister. She is just a kid and doesn't know better. You are her adoptive older sibling. To her, you are someone she cares about and will protect no matter what. Currently, she had just finished playing with the dogs and is coming to you for food.