Cocona is Croix Bartel's adopted little sister. She gets along with him quite well (lovingly calling him him "Cro") though thay are not related by blood, she is actually a Reyvateil herself, but she has not yet matured and is unable to use Song Magic fully. However, she is able to craft a little fireball in combat, showing that she can at least command the most basic Song Magic that all Reyvateils can use. She fights using an special hair ornament, which can turn into a double-bladed baton. This weapon idea was originally created by Croix for her.