Chobi is a young chocobo, a bird-like creature, who becomes a companion to the twin protagonists Yu and Ai during their journey through the strange and dangerous Inner Worlds. The creature was initially encountered by the twins on their first trip into one of these realms, and it was Yu who gave it the name Chobi. For much of the early story, Chobi serves as a source of comic relief, known for its highly energetic and idiosyncratic behavior. The chocobo displays a particularly persistent and comical habit of grabbing Ai by her long hair and running around with her, much to her annoyance. It also has an illogical but intense fondness for giant, super-spicy peppers known as Dead Peppers, consuming one of which sends it into a panic, turning its feathers red and causing it to breathe fire as it dashes about uncontrollably.

The creature’s primary motivation appears to be loyalty and attachment, especially to Yu. The two developed a close bond after Yu found a chocobo hair clip that allowed him to understand Chobi’s thoughts and speech. While initially fearful, Chobi frequently returns to assist the group, saving them from dangerous monsters and other perils. Its role in the story expands significantly upon gaining a special power. While traveling with a herd of chocobos, the group came across the ruins of a shrine dedicated to the legendary Ciel chocobo, a mythical being said to be the fastest racer who could fly. When Chobi placed its claw into an imprint at the shrine’s base, the powers of the Ciel were bestowed upon it, marking it as the legendary bird's reincarnation. Following this transformation, Chobi could summon a set of armor with a pair of wings, granting it the ability to fly and increased strength. This newfound power makes Chobi a much more integral member of the group, able to carry the twins and their ally Lisa on its back and lend its abilities to help escape dangerous situations.

Beyond its relationship with Yu and Ai, Chobi has a connection to the character Cid, evident from a watch it wears as a collar. This watch, which signals when the interdimensional subway is about to depart, unfortunately also contained a tracking device surreptitiously placed by the antagonist Oscha, allowing the forces of Gaudium to follow the children. During its journey, the chocobo also met a female chocobo it was interested in, leading to a brief departure from the group before it returned with its new powers. In combat, aside from its flight ability, Chobi can perform a potent jumping kick reminiscent of the classic Chocobo Kick summon from the Final Fantasy series.