Yubaba and Zeniba are twin sister witches inhabiting the spirit world. Physically near-identical, they possess large heads, blonde hair tied in buns, wrinkled faces with prominent hooked noses, red dots between their eyes, blue eyeshadow, large golden earrings, and dark blue dresses with ruby brooches. Zeniba sometimes wears glasses during tasks like weaving, marking a distinction from her sister.

Yubaba rules as proprietor of a grand bathhouse, wielding strict authority over employees. She binds them through magical contracts that steal their true names. Greed motivates her, prioritizing gold and business, yet she exhibits genuine maternal love for her son Boh, confining him in a lavish, cushioned room to shield him from germs. Her management blends intimidation with rare recognition, such as publicly praising Chihiro after servicing the River Spirit. Her formidable magic includes transformation (turning humans into animals), pyrokinesis, telekinesis, flight via a bird-like form, and inflicting memory manipulation or parasitic control using a black slug.

Zeniba initially seems antagonistic, pursuing Haku with lethal paper shikigami after he steals her golden seal. She transforms Boh, Yubaba's bird, and the Three Heads into diminutive forms during a bathhouse confrontation and threatens Chihiro into silence. Her demeanor shifts when Chihiro visits her secluded cottage at Swamp Bottom to return the seal and apologize. Zeniba warmly welcomes Chihiro, offers tea, reveals Yubaba placed the parasitic slug in Haku, and grants forgiveness. She guides Chihiro on reclaiming Haku's identity, offers sanctuary to No-Face as a weaving apprentice, and personally absolves Haku of his theft. Her magic matches Yubaba's in power, specializing in paper charm manipulation, astral projection, sensing, and enchanting objects like Shikigami or a Hopping Lantern.

Despite their shared appearance and history, their lifestyles and values diverge. Yubaba thrives within a bustling, profit-driven enterprise, symbolizing oppressive authority and transactional relationships. Zeniba lives contentedly in rural solitude, embodying wisdom, patience, and nurturing community. She rejects enslavement, preferring enchanted objects for help. Yubaba remains largely unchanged, honoring bargains pragmatically but retaining core self-interest, while Zeniba transitions from vengefulness to benevolence after the seal's return. Their dynamic reflects a duality within a single entity, representing opposing societal facets: the demanding professional versus the compassionate private self, positioning them as manifestations of fragmented identity.

Their conflict centers on the stolen golden seal, an item of significant magical power. Yubaba orders Haku to steal it, triggering Zeniba's curse and retaliation, underscoring their estrangement. Zeniba ultimately dismisses the seal's importance, highlighting her detachment from materialism compared to Yubaba.

Both sisters profoundly influence Chihiro's journey. Yubaba's contract forces Chihiro into labor, catalyzing her maturation through adversity. Zeniba's forgiveness and counsel empower Chihiro to rescue Haku and her parents. Chihiro addresses both as "Granny," acknowledging their roles in her transformation.