Dema, full name Demaku de Frigidus of Meikaina, is one of the main Cures and a third year middle school who hails from the kingdom of fairies, Meikaina. She's a very shy, sensitive young girl who can come off as rude to others. She doesn't understand social cues very well, and can be quite suspicious of others at first glance. She has low self-esteem, often putting herself down and comparing herself to others. She used to be more meek and a crybaby, but after she first became a Cure,  she decided to become more confident like the others. Dema was to be crowned princess of her kingdom, and was very sheltered growing up. However,  on the day of her coronation, her kingdom was attacked. In the attack, she lost her parents and got transported to Michigaoka, the main town the series takes place. Given the surname Yukihana, she was adopted, but was later informed a long while after that her adoptive parents have died. Now, living with her adoptive aunt and uncle, Dema starts a new life for herself, fascinated by the Pretty Cure. Dema transforms into Cure Frost, the Pretty Cure of Snow/ice, Memories, and Confidence. 

English Dub Sailor Moon is a good example for how her Cure Form should sound. In earlier episodes, Dema sounds very shy and soft-spoken, somewhat high-pitched quiet and soft voice. A little bit more confident later on, but still a very soft voice. As Cure Frost,  her voice deepens slightly and she sounds more serious and confident.