Sailor Chibi Chibi Moon was Chibi Chibi's Sailor Senshi form, and in some continuities, an alternate form of Sailor Cosmos. She appeared in the Sailor Stars season of the anime and the Stars arc of the manga, as well as several of the musicals.
In the original manga, she was known simply as Sailor Chibi Chibi, but in the reprint manga she was renamed "Sailor Chibi Chibi Moon" to match her anime name.
In this Senshi form, she carried a scepter in the form of a heart with what looked like a planetary ring, and used it to defend herself and Sailor Moon. She was not shown using any attacks of her own, but she did increase Sailor Moon's power.
In the anime, Sailor Galaxia sealed Chaos inside of herself to end the Sailor Wars in the long past. Realizing that Chaos was corrupting her body, she removed her Star Seed and sent it far away. When her Star Seed reached the Earth, it took the form of Chibi Chibi and pretended to be Usagi's sister. She was the Light of Hope that the Sailor Starlights were looking for, and the only way they thought they could beat Sailor Galaxia.
During the final fight against Galaxia, Chibi Chibi awakened as the Light of Hope, and Galaxia recognized her as the same power that she had released so long ago. The Light of Hope instructed Sailor Moon to fight with the Sword of Sealing to defeat Sailor Galaxia, but she refused to fight. Galaxia would not cease her attack, but Sailor Moon only used the Sword of Sealing to defend herself. As she did, she accidentally injured Galaxia, who then used her own sword to shatter the Sword of Sealing.
Sailor Chibi Chibi Moon then reappeared in her human form, and Sailor Moon held her, crying, until she faded away.
Sailor Chibi Chibi Moon appeared three times in the anime. The first time was in episode 187, when Sailor Aluminum Seiren tried to take Sailor Moon's Star Seed. Chibi Chibi, trying to help Sailor Moon, picked up the Eternal Tiare and became Sailor Chibi Chibi Moon. In episode 191, she became Sailor Chibi Chibi Moon upon finding Princess Kakyuu's incense burner.
In episode 196, Sailor Chibi Chibi Moon showed up again to teleport Sailor Mars, Sailor Venus, Sailor Jupiter, Sailor Mercury, and Sailor Moon into Ginga TV to face Sailor Galaxia in her warped throne room. When the battle became too intense, she later teleported them back out of the throne room in a ball of pink light. She remained in her Senshi form for the rest of the season.
She powered up Sailor Moon's attack, giving her the ability to perform Silver Moon Crystal Power Kiss.
Sailor Chibi Chibi Moon first appeared in the manga in Act 46, when Princess Kakyuu realized that Chibi Chibi was also a Sailor Senshi. When Sailor Galaxia attacked Sailor Moon in Act 47, Sailor Chibi Chibi Moon saved her and forced Galaxia to retreat. She accompanied the others to Sagittarius Zero Star and there revealed that her true form was Sailor Cosmos. She was from the far future, where she lost the war against Chaos. Being desperate, she went to the past to have Sailor Moon destroy the Galaxy Cauldron. Sailor Moon refused, because destroying the Galaxy Cauldron would mean that no new stars or souls would be born.
- Chibi Chibi Crystal Power, Make Up - Used to transform into Sailor Chibi Chibi Moon.
In both the anime and manga, Sailor Chibi Chibi Moon wore a sailor fuku similar in design to those of the Solar System Senshi. Her collar and skirt were blue, while her bows were red, with a pink heart in the center of her front bow. She also had pink heart earrings, and pink heart-shaped covers on her odango with yellow accents around them. She wore two belts, one yellow and one red. Her sleeves were white puffs with red and yellow trim. She wore wrist length gloves similar to those of Sailor Uranus and Sailor Neptune, with red and yellow accents at the ends. Her boots were white with red trim and pink hearts on them. Her tiara gem was a pink heart.
In the musicals, Sailor Chibi Chibi Moon was played by Mao Kawasaki, Mikiko Asuke, Yuka Gochou, and Mina Horita.
Sailor Chibi Chibi's costume had a similar design to that of the anime and manga. Her collar was blue with gold accents. She had white puffy sleeves. Her skirt usually had three layers, the top one blue, the middle one silver, and the bottom one pink, though later versions had an entirely blue skirt. Her bows were a dark pink and she had a pink heart in the center of the front bow. Unlike in the anime and manga, her gloves extended to her elbows. Her glove fittings were gold and pink. Her boots were white with dark pink horizontal borders and pink hearts on top. She had two belts, one gold and one pink. She also had pink earrings in the shape of hearts, as well as a pink heart in the center of her tiara. Her odango covers were pink with gold pearly accents. All the trim on her costume was gold.