Age: 11
Height: 130 cm
Weight: 28 kg
Birthday: February 19th
Blood type: B
Three sizes: 62-50-65 cm
Hobbies: "What are hobbies?"

Absent-minded and innocent, Kozue is a young child recruited by the producer that resembles a fairy. Naturally inquisitive, it is hinted that Kozue has lived a sheltered life until the start of her idol career. Always drowsy, Kozue tends to doze off frequently and in her lines tends to elongate end vowels and speaks entirely in hiragana.

In the tie-in Cinderella Girls Theater strips, Kozue is shown to have a sister-like relationship with Aya Kirino. Despite not sharing many things in common, Kozue and Aya bonded over Aya's secret hobby of doll collecting. This duo is known as Yousei and Onee-san.

In Starlight Stage, the producer first met Kozue while she was asleep outside beside him. Upon waking her up she says she just awoke from a nice dream that was "warm, and sparkly". Asking if she would like to do something more fun, and telling her that "idols are people that bring smiles", he recruited her. In the Sun High Gold event, Mio Honda has to accompany her in order to communicate more "normally". Under Mio's guidance, Kozue speaks with much less ellipses, while still retaining her usual hiragana-only lines and elongated end vowels

(Source: Project-iM@S)