Cosette is a very calm and cunning young woman. She loves to rile up Silvia by revealing things she'd rather keep secret, though she doesn't do so maliciously. She is extremely devoted to Silvia, and will do anything needed for her.
Cosette is a beautiful young woman with short dark blue hair, and a figure resembling that of Silvia's. She is always wearing her maids uniform.
Cosette is a mistress of disguise, in that she was able to pass herself off as Silvia to such an extent that, by looks alone, no one (not even her sister) could tell. She also seems to have almost supernatural skills in stealth that she can vanish from sight, even while someone is watching. She is a skilled fighter, able to knock several daggers out of the air with ease, and then defeat her opponent, a skilled warrior herself, in moments.
- The Shelly family seems to be composed entirely of bodyguards and maids for the Lautreamont Royal Family.