Seraphina, the youngest child of the demon king of Lustra and twin to her brother Seros, found an unconscious person and brought them home. Seraphina and Seros are inseparable twins who share everything. Seraphina often falls asleep while wandering, singing a lullaby that can induce eternal sleep in others. She and Seros were born with Reda Disorder, a condition that prevents demons from shifting into humanoid forms. They have red skin, white hair, and yellow eyes. Seraphina is described as somewhat simple-minded and an airhead but generally not bad for a demon.