|Queen of Sauville|
|Name in Japanese||ココ•ローズ|
|Romaji Translation||Koko Rōzu|
|Debut (Anime)||Gosick Episode 13|
|Debut (Light Novel)||Volume IV|
|Appears in||Light Novels, Anime|
|Voice Actor (Japanese)||Aya Hisakawa|
|Place of Birth||France|
|Family||Rupert de Gilet (husband)|
|Profession||Queen of Sauville (1897-1914)|
|Affiliation/s||Sauville Royal Family|
Her pet name is "the Blue Rose", and signed photographs of herself are famous with girls throughout France. In her journey from France to Sauville, she is accompanied by her personal maid, whom she is very close to. She initially resided in the royal palace with her husband Rupert de Gilet, due to not being able to conceive a child for the king, she was transferred to a lavish country house.
Rumors that circulate in Sauville say that Coco Rose obtained a magical stone which makes her invisible by holding it, and she reportedly used this newly-acquired power to go to places outside of the country house where she usually stays.
It is revealed by Victorique that she had an affair with Leviathan the Alchemist (who was an African) for whom she fell in love with. Their child was a mulatto, a mix of Caucasian and African bloodlines, and to prevent the king from killing her and the child when he found out, a switch took place between her and her trusted friend and maid (who looked like her) and escaped with her child.
After the queen's maid's death, the king assigned a lookalike, a former dancer named Nicole Leroux, to act as Coco Rose's replacement. The king would later kill Nicole to keep Nicole's true identity a secret.The king did not know about the maid and the queen switching places but killed the maid thinking that he wanted to preserve their love the way it was before Leviathan came.
Coco and her son survived (their carriage broke down and they hitched a ride home with Victorique and Kazuya Kujo). They look sadly on the academy as the clocktower where the queen and Leviathan used to see each other was taken down.