Chibi Chibi appears to be around two years old and has limited speech abilities, knowing only a few simple words and often repeating what others say. In the manga, she mainly imitates the ends of other people's sentences, while in the anime, she predominantly says "chibi." Her red hair is styled in two heart-shaped odango buns with small ringlets sticking out from the sides, resembling the hairstyle of the protagonist, Usagi Tsukino.
In both series, Chibi Chibi quickly becomes attached to Usagi's family, whose memories are altered so they believe her to be their youngest child—a situation similar to when Chibiusa first appeared. Only Usagi retains her original memory, and due to Chibi Chibi's toddler-level conversational skills, the Sailor Senshi cannot question her effectively.
Chibi Chibi eventually transforms into a Sailor Senshi on her own. In the manga, she is named Sailor Chibi Chibi, whereas in the anime, she is called Sailor Chibi Chibi Moon. In the manga, Chibi Chibi transforms by shouting, "ChibiChibi Crystal Power! Make Up!" This transformation sequence is never shown on screen in the anime.
The true identity of Chibi Chibi differs significantly between the manga and the anime, largely because both were produced concurrently.
In the manga:
- Chibi Chibi's childlike form is actually a disguise for Sailor Cosmos, an immensely powerful Senshi from the future and Sailor Moon's ultimate form.
In the anime:
- Chibi Chibi is the starseed of Sailor Galaxia, who was once a great force for good. When Galaxia fought Chaos, she saw no way to defeat it except to seal it within her own body. To protect her starseed from corruption, she sent it to Earth, where it became Chibi Chibi and befriended Sailor Moon. The Starlights refer to Chibi Chibi as the "light of hope"—their chance to defeat Galaxia. She can transport herself and the Senshi freely around Galaxia's domain and ultimately transforms into the Sword of Sealing, the same sword Galaxia used to contain Chaos.
Chibi Chibi's two identities should not be conflated. Sailor Cosmos does not appear explicitly in the anime, though a silhouette of Chibi Chibi as an adult is sometimes mistaken for her. In the manga, Galaxia's starseed is not humanoid and has no connection to Chibi Chibi or Sailor Cosmos.
