Yubaba rules as proprietor of the spirit realm's bathhouse, its undisputed authority. She is the identical twin sister of Zeniba and mother to a large infant son, Boh. Her imposing appearance features an oversized head, a prominent crooked nose bearing a mole between the eyebrows, lavender eye shadow, and gray hair secured in a bun. Golden earrings and opulent clothing complete her distinct visual presence, notably lacking the glasses worn by her twin. Her personality blends authoritarian control, professional diligence, and selective maternal devotion. She enforces rigid bathhouse hierarchies, binding workers with contracts that seize their true names—a magical act preventing escape unless they recall their original identities. This practice underscores her prioritization of operational control and profit, frequently manifesting as greed. Yet she displays genuine care for Boh, confining him to a lavish nursery due to exaggerated germ fears and reacting with intense distress to his endangerment. She also exhibits professional integrity, personally managing hazardous situations like the Stink Spirit's arrival and publicly acknowledging employees like Chihiro after their service to the River Spirit, declaring celebratory drinks for the staff. Her extensive magical abilities encompass telekinesis, pyrokinesis, energy projectile attacks, flight through bird-like transformation using a cloak, and reality-altering spells. She transforms humans into animals, erases or manipulates memories, infests individuals with control slugs, and enforces magically binding contracts. Her power is nearly matched only by Zeniba, cementing her formidable status. Yubaba's actions drive significant narrative events. During Chihiro's arrival, she intimidates her into employment, rebrands her as "Sen" by stealing part of her name, and assigns Haku to oversee her. She later commands Haku to steal Zeniba’s golden seal, indirectly causing his near-fatal curse. When No-Face rampages, Yubaba initially blames Chihiro, dismisses Boh (transformed into a mouse), and forces Chihiro to confront the spirit alone. Upon discovering Boh's disappearance, she negotiates with Haku: his safe return in exchange for releasing Chihiro and her parents. She honors this agreement, subjecting Chihiro to a final test to identify her parents among pigs before permitting their departure. Culturally, her character draws from the Japanese yamauba—mountain witches transforming humans into prey while exhibiting fierce motherhood. Conceptually, she represents workplace duality, symbolizing contrasting professional and personal personas. Her bird transformation pays homage to *Krabat*, while her energy attack references *Dragon Ball*'s Kamehameha technique. Her relationship with Zeniba is defined by mutual animosity and opposing values; Zeniba embodies domestic kindness against Yubaba's transactional efficiency. Despite conflicts, both sisters are addressed as "Granny" by Chihiro's conclusion, indicating thematic unity as wisdom figures. Boh's exposure to the outside world catalyzes subtle growth in Yubaba; his newfound independence and defiance—threatening to dislike her if she harms Chihiro—compel her reluctant adherence to spirit realm rules during Chihiro’s departure.