In the future, Japan suffers a catastrophic event that destroys its land and halts progress. The emperor and his four sons rule with an iron hand, and only the "Child of Destiny" can break free from their control. Sarasa, twin sister of Tatara, the prophesied child, supports her brother despite living in his shadow. Tragedy strikes when the emperor's youngest son, the Red King, attacks her village and kills Tatara. Sarasa takes on her brother's identity as the Child of Destiny to avenge his death.
Sarasa's health suffers from the sudden turn of events, and she seeks refuge in a hot spring to recuperate. There, she meets a charming and enigmatic young man named Shuri. Sarasa treats him differently from other girls, and he is fascinated by her. Their casual encounter seals their fate, as they are bound together by war, hatred, and love.
