ChibiChibi
Chibichibi first appears in Act 44 of the manga and Episode 182 of the anime. She appears to be about two years old, and cannot really talk yet: she imitates the ends of others' sentences, and mostly says "chibi". Her red-pink hair is always up in two heart shaped odango with little ringlets sticking out the sides, echoing Usagi's hairstyle. In each series, Chibichibi immediately attaches herself to Usagi's family, whose memories are modified so that they believe her to be the youngest child—almost exactly what Chibiusa had done on her first appearance. In each series, Chibichibi is the caretaker of a small, ornate censor that releases a scent of osmanthus, which the Sailor Starlights gradually recognize as a symbol of Princess Kakyuu. They threaten Chibichibi and try to take it away from her, and Kakyuu herself is revealed to have been resting inside it, hidden from the evil Sailor Galaxia.
In the anime, she meets Usagi in the park one afternoon and starts to follow her around, saying only "chibi chibi" (without having been prompted). Setsuna states that Usagi herself only has one child, so Chibichibi cannot be Usagi's and Mamoru's second child.
In the manga, she is shown floating down to Earth with an umbrella in her hand, and then simply shows up at the door of the Tsukino house. When Usagi's mother expresses surprise, asking "Chibiusa?" the little girl repeats "Chibi chibi?" and receives her nickname. Here, Setsuna says that any Queen of the Moon Kingdom line will have only one daughter when Usagi starts to wonder if Chibichibi was hers and Mamoru's second child. Usagi then suspected that Chibichibi was Chibiusa's child in the future. But when Chibiusa meets Chibichibi, she feels very strongly that Chibichibi is not hers.
Chibichibi eventually transforms, under her own power, into a Sailor Senshi. In the manga she is simply named Sailor Chibichibi, while in the anime she is called Sailor Chibichibi Moon. Although the reprint of the manga continues to omit the word 'moon', it is added to her name on a sticker included with Volume 12. In the manga, Chibichibi transforms into a Sailor Senshi by shouting the words "Chibichibi Crystal Power! Make Up!" This transition is never shown on screen in the anime. In this Senshi form, she carries a heart scepter with what looks like a planetary ring and uses it to defend herself and Sailor Moon. She is not shown using any attacks of her own, but she does increase Sailor Moon's power in both the manga and the anime.
The truth of Chibichibi's identity is very different in the manga from what it is in the anime, largely because the two series were being produced at roughly the same time. In the manga, Chibichibi's childlike form is really a disguise for Sailor Cosmos, an ultimately-powerful Senshi from the future. In the anime, Chibichibi is the starseed of Sailor Galaxia, who had once been a great force for good. When Galaxia fought Chaos, she could see no way to defeat it except to seal it away inside her own body. In order to protect her starseed from being corrupted, she sent it away to Earth, where it finally becomes Chibichibi. Chibichibi is also referred to as the "light of hope" (kibō no hikari) by the Starlights; their one chance for defeating Galaxia. She is able to transport herself and the Senshi around Galaxia's domain freely, and in the end, transforms herself into a Sword of Sealing (fuuin no ken). This is the weapon Galaxia had used to seal away Chaos, and Chibichibi begs Sailor Moon to use it to defeat them.
In the anime, she meets Usagi in the park one afternoon and starts to follow her around, saying only "chibi chibi" (without having been prompted). Setsuna states that Usagi herself only has one child, so Chibichibi cannot be Usagi's and Mamoru's second child.
In the manga, she is shown floating down to Earth with an umbrella in her hand, and then simply shows up at the door of the Tsukino house. When Usagi's mother expresses surprise, asking "Chibiusa?" the little girl repeats "Chibi chibi?" and receives her nickname. Here, Setsuna says that any Queen of the Moon Kingdom line will have only one daughter when Usagi starts to wonder if Chibichibi was hers and Mamoru's second child. Usagi then suspected that Chibichibi was Chibiusa's child in the future. But when Chibiusa meets Chibichibi, she feels very strongly that Chibichibi is not hers.
Chibichibi eventually transforms, under her own power, into a Sailor Senshi. In the manga she is simply named Sailor Chibichibi, while in the anime she is called Sailor Chibichibi Moon. Although the reprint of the manga continues to omit the word 'moon', it is added to her name on a sticker included with Volume 12. In the manga, Chibichibi transforms into a Sailor Senshi by shouting the words "Chibichibi Crystal Power! Make Up!" This transition is never shown on screen in the anime. In this Senshi form, she carries a heart scepter with what looks like a planetary ring and uses it to defend herself and Sailor Moon. She is not shown using any attacks of her own, but she does increase Sailor Moon's power in both the manga and the anime.
The truth of Chibichibi's identity is very different in the manga from what it is in the anime, largely because the two series were being produced at roughly the same time. In the manga, Chibichibi's childlike form is really a disguise for Sailor Cosmos, an ultimately-powerful Senshi from the future. In the anime, Chibichibi is the starseed of Sailor Galaxia, who had once been a great force for good. When Galaxia fought Chaos, she could see no way to defeat it except to seal it away inside her own body. In order to protect her starseed from being corrupted, she sent it away to Earth, where it finally becomes Chibichibi. Chibichibi is also referred to as the "light of hope" (kibō no hikari) by the Starlights; their one chance for defeating Galaxia. She is able to transport herself and the Senshi around Galaxia's domain freely, and in the end, transforms herself into a Sword of Sealing (fuuin no ken). This is the weapon Galaxia had used to seal away Chaos, and Chibichibi begs Sailor Moon to use it to defeat them.
Sailor Cosmos
Sailor Cosmos reveals herself in the final Act of the manga. She comes from a future which has been all but decimated by the battle with Sailor Chaos; after ages of fighting, she despairs and flees to the past as the infant Chibichibi, to encourage Eternal Sailor Moon to defeat Chaos in the final battle of the series. At first, she wants Sailor Moon to destroy the Galaxy Cauldron altogether, ensuring Chaos' destruction, but Sailor Moon protests, realizing that if the Cauldron is destroyed no more stars will be born, leaving the Galaxy without a future. She chooses to sacrifice herself to the Cauldron and seal Chaos away, which Cosmos finally realizes to have been the right decision. Reminded of the strength and courage she herself needs to have, she returns to the future with new hope.
The manga implies that Sailor Cosmos is the ultimate form of Sailor Moon; this fact is confirmed in a magazine interview with Naoko Takeuchi. What this means exactly is heavily debated among fans. None of Sailor Cosmos's powers are directly shown. Nevertheless, it is implied in the final chapter of the manga that the ability to lose everything or gain everything is a defining characteristic of being Sailor Cosmos.
Sailor Cosmos never makes an appearance in the anime series, although the silhouette of Chibichibi's adult form (the "Light of Hope") bears a strong resemblance to her.
The manga implies that Sailor Cosmos is the ultimate form of Sailor Moon; this fact is confirmed in a magazine interview with Naoko Takeuchi. What this means exactly is heavily debated among fans. None of Sailor Cosmos's powers are directly shown. Nevertheless, it is implied in the final chapter of the manga that the ability to lose everything or gain everything is a defining characteristic of being Sailor Cosmos.
Sailor Cosmos never makes an appearance in the anime series, although the silhouette of Chibichibi's adult form (the "Light of Hope") bears a strong resemblance to her.