An introvert misanthrope who prefers living a secluded and quiet life, away from other people and close with her books, or as she treats them with love and refer them as "Children". Ui has an affinity towards reading and taking care of books. She also despises strangers who come into her library or even just wanting to say hi. She spends most of her life in the Antiquarian Library, sleeping, eating, everything. Although she wants to take good care of her friends if she had one.