The characters in the series include but are not limited to:


Yū Morisawa (森沢優 Morisawa Yū?) / Creamy Mami (クリィミーマミ Kurīmī Mami?)
Seiyū: Takako Ōta
A normal 10-year old girl, Yū harbours a secret crush for her childhood friend Toshio Ōtomo. Given the ability to transform into a 16-year old girl, she is made to fill in for the absent Megumi Ayase to sing on TV. Giving her name as Creamy Mami, she becomes an overnight hit.


Nega (ネガ Nega?)
Seiyū: Kaneta Kimotsuki
One of the two cats from the Feather Star asked to watch over Yū Morisawa while she has magical powers. His name is short for negative. Nega was the one who taught Yū the words which allow her to transform in Creamy Mami, he secretly know other magical words, but avoid telling then since Yū might end up using her powers for self gain like cheating in a surprise school test. Yū tricked him into saying the magical words to generate a pen which can answer any questions in one of the episodes. He, despite his brash attitude, really likes Yū a lot that he was even able to mistook a girl called Cassidy with her.


Posi (ポジ Poji?)
Seiyū: Yūko Mita
One of the two cats from the Feather Star asked to watch over Yū Morisawa while she has magical powers. Her name is short for positive. She is very supportive of Yuu and it sometimes annoy Nega. When Yū failed to transform for the first time, she suggested to use the magic wand while saying the magic words which led to a successful transformation. Her voice actress also say the titles of every episodes.


Megumi Ayase (綾瀬めぐみ Ayase Megumi?)
Seiyū: Saeko Shimazu
A spoiled and selfish idol who is the star act of Parthenon Productions, she feels threatened by the newcomer, Creamy Mami, and declares herself to be Mami's rival.


Hayato Kidokoro (木所 隼人 Kidokoro Hayato?, Kidokoro-Manager, 木所マネージャー Kidokoro Manējā)
Seiyū: Sukekiyo Kameyama
Megumi Ayase's bumbling manager, he is moved to managing Creamy Mami when she joins Parthenon Productions.


Midori Kisaragi (如月みどり Kisaragi Midori?)
Seiyū: Masahiro Anzai
Toshio Ōtomo's best friend, Midori is in love with Yū Morisawa and seeks to tell her this. Because of his bashfulness, he needs Toshio's help to do this.


Natsume Morisawa (森沢なつめ Morisawa Natsume?)
Seiyū: Mika Doi
Wife of Tetsuo, mother of Yū, Natsume works in Creamy with her husband. She used to be the leader of a motorcycle gang. Her and her husband own Creamy Crepe making crepes.


Tetsuo Morisawa (森沢哲夫 Morisawa Tetsuo?)
Seiyū: Akira Murakami
Husband of Natsume, father of Yū, Tetsuo works in Creamy with his wife. He used to be a member of Natsume's motorcycle gang. Tetsuo almost discovered Yû when she transformed for the first time, however she managed to trick him.


Toshio Ōtomo (大伴俊夫 Ōtomo Toshio?)
Seiyū: Yū Mizushima
Friend of Yū Morisawa and Midori Kisaragi, he falls in love with Creamy Mami after her first TV appearance. But in the end he finally understands that Mami was Yuu all long. He was in love with Yuu all this time and didn't know.


Pino Pino (ピノピノ Pino Pino?)
Seiyū: Seiko Nakano
An alien being, Pino Pino grants Yū Morisawa magical powers for one year in thanks for helping him find the Feather Star.


Shingo Tachibana (立花慎悟 Tachibana Shingo?)
Seiyū: Kazuhiko Inoue
President of Parthenon Productions, he quickly recognises Creamy Mami as future sensation, and tries to make her into a star.


Mamoru Hidaka (日高 守 Hidaka Mamoru?)
A boy which recently got transfeRred to Yû's school who came from a small town in Hokkaido. He seemed to be pretty rude at first, but later became friends with Yû due his huge love for cats. He says he can listen what the wind says and was one of the few people who realized Nega and Posi aren't normal cats. Mamoru at first doesn't knew many things about big cities and was annoyed due the fact Creamy Ga-Oka had such small threes. He was pretty outdated with news that he even doesn't knew who Creamy Mami was, plus when asked he thought it was a name of a crepe. Despite being a major character, Mamoru never had any real contact with Mami.