Yuni/Blue Cat/Cure Cosmo

Yuni (ユニ) is one of the five main characters of Star☆Twinkle Pretty Cure who sometimes ends her phrases with "~meow". Yuni's alter egos are Blue Cat (ブルーキャット), the phantom thief, Mao (マオ), Bakenyan and Cure Cosmo.

Appearance
Yuni resembles a humanoid cat with cream-colored fur. Her hair is still dodger blue but is styled differently with giant rounded twin tails with golden rings at each end as well as black and white cat ears. Her eyes are shaped slightly differently and she also has a dark brown nose and twin white whiskers. She wears a navy blue bodysuit with a white rounded collar lined with pink and a rainbow-colored brooch. Attached to the bodysuit are puffy white and pink shorts with her black tail jutting out. Her bracelets are thick and gold with blue arm warmers attached and her shoes are white and blue with thick gold anklets.

As Mao, she has lavender magenta-colored hair that just reaches her shoulders. On her head are two pale pink balls of cloth that are tied onto her head with yellow beads. She has lime green eyes and on her ears are gold earrings. Her outfit is mainly pink, with a white-collar that has a giant magenta bow attached to it. On the center of the bow is a gold bell. On the front of her shirt are two gold buttons, and she wears a blue belt around her waist. Her skirt is separated into two colors; pink and white with two layers underneath: a pale blue layer with a frilly pale yellow layer underneath that. She wears yellow beads on her arms, and white gloves as well as blue boots with a white frilly top that has yellow beads. She also has a black cat tail with a large pink bow attached to it by a gold band.

As Blue Cat, her hair turns dodger blue and is tied into braids by a gold tie. She wears a dark blue top hat with a pale blue and black pattern near the rim. She also wears giant blue glasses with light pink frames that hide her light orange eyes and a dark blue choker with a gold pendant. Her outfit is a dark blue tailcoat with a white collar and layer underneath. Her skirt is pleated and blue. She wears white gloves that reach her shoulders with blue gloves that reach her wrists on top. Her boots are blue and her thigh high socks are white. Her cat tail is black. Underneath her hat is a pair of black and white cat ears. Yuni retains this outfit in her human form, minus the hat and the glasses.

As Cure Cosmo, her hair grows longer and becomes a lighter shade of blue with magenta streaks on the twin tails. The ends are curled upward and held on each side with a large yellow triangular clasp. She also has two triangle-shaped hair clips on each side of her head, along with a small blue top hat with a star-shaped rainbow jewel on the right side. Her cat ears are black and slightly rounded with white fur tufts inside. Her eyes become light orange. The bodice of her dress is dark blue with a white rounded collar and a white insert with two golden buttons in the middle of it along with a light pink translucent cape. At the top of her chest is her Star Color Pendant. The top of her skirt is lined with white fur and the pleats of the skirt are each a different color of the rainbow. There is also a white scalloped layer and a long light pink and translucent scalloped layer. Around her neck is a black choker with a round gold pendant along with triangular earrings. She also wears dark blue opera-length gloves and dark blue knee-length boots, both lined with white fur. There are gold star designs on the lower part of her gloves and yellow triangles jutting from the lower part of her boots. Her black cat-like tail has a light blue ring around the end of it.

Personality
As Mao, she is very friendly and acts cutesy towards others. As it later turns out, it was merely an act she puts on to conceal her true identity as a thief.

As Blue Cat, she is shown to be cunning by using the bright fireworks to make her break with the Princess Star Color Pen and Madoka's plan to use the star donuts as bargaining chips to win the pen at the Auction. According to Lala, she always gets what she seeks.

Putting her aliases aside, Yuni tends to prefer being a lone wolf and generally holds a strong responsibility for herself mainly rooted from the guilt she has of being unable to save her planet Rainbow, rejecting her friends' kind offers and assistance in the beginning and blaming herself when she fails to accomplish her goals, but she gradually warms up around them as the series goes on. Owing to her past career as Blue Cat, she has a bad habit of stealing as demonstrated in episode 22. Despite all this, Yuni is still kindhearted, and she will still help and rescue the needy whether her foes or friends, as seen in episode 21 and episode 23 when she as Cosmo purified Aiwarn and rescued Fuwa respectively. In episode 24, it is shown that she has a passion for singing, which can explain why she sometimes uses her space idol alias Mao.

Despite being a major heroine, Yuni is overall a morally gray character: on one hand she is learning to be heroic enough to save the universe and cares for her friends, but on the other hand, she still thieves for the plundered treasures of Planet Rainbow. She has a habit of teasing people too, particularly Mary Ann the assistant inspector of the police department.