When a swarm of giant bugs threatens to wipe out humanity, the world's only defense is a group of humans with special abilities called Butterflies. For Maehwa Baek, Butterflies are just heroic people he sees on TV until a tragic event brings him to the scientists that created them. Soon, Maehwa must confront questions about himself that he has long avoided: why does he lose control at the sight of his own blood? And what happened during the 13 years of his life that he can't remember?

Once upon a time, the world had been divided into the Moon Kingdom, inhabited by humans, and the Sun Kingdom, inhabited by demons. Estelle, a knight of the Moon Kingdom, loses her family to an ambush from the demons and is sentenced to life in exile after becoming entangled with a mysterious demon child. To survive, she sets out to a mysterious tower in the north with her companions. A timid knight, a slave boy, and a shadow who was once the Demon King.This is an alluring story about three people embarking on an adventure to find their true selves.