B'T Jutaime functions as the mechanical companion to Fou Lafine in the Machine Empire's hierarchy. Her design is inspired by the Chinese mythological Vermilion bird of the South, also known as a phoenix or hō-ō bird.

Destroyed by Quattro, Jutaime experiences resurrection when Fou Lafine plays the "song of the angels" on his violin. This act unlocks her latent revival ability, transforming her into her "true phoenix" form. Her visual appearance shifts from vermilion to emit a distinctive pinkish luminescence in this state.

Jutaime wields significant independent combat power, effectively employing her wings and sharp claws during pursuits and engagements like her solo confrontation with Crow. Her primary offensive technique is "Deadly Carol," a sonic attack designed to disrupt or destroy a target B't's control system or "mind." This attack induces hallucinations of angels and skeletons, causing mental collapse. Its effects can be negated by disabling auditory reception and do not affect humans.

An amplified version, "Fortune Symphonic," manifests when Fou simultaneously plays a specific song on his violin. This enhanced ability facilitates psychological and emotional connections between Fou and those within hearing range. Her resurrection ability remains passive, activating only upon her death through the catalyst of Fou's violin performance, culminating in her true phoenix transformation.

Narrative descriptions consistently use feminine pronouns for Jutaime. Her name originates from the French phrase translating to "I love you."