Since childhood, Princess Sakura was instructed never to look at the moon, though no explanation was ever given. Now 14 years old, she fears her upcoming marriage to her fiancé, Prince Oura, a man she has only ever known through correspondence. Having lost her family, she lives as an outcast in a village while waiting for her wedding day. When the prince's emissary, Aoba, arrives to escort Sakura to the palace, the rebellious princess attempts to flee to avoid the union. During her escape, she accidentally sees the full moon, prompting a demon to attack her. After Aoba saves her, Sakura learns that she is the granddaughter of Princess Kaguya and an immortal youko—just like the demon that fell from the sky. Armed with the legendary Chizakura blade, Sakura is now charged with defeating the youko that threaten those closest to her. Her mission is linked to her Soul Symbol—a single kanji character that reveals a person's true nature at birth. Sakura's symbol signifies "destroy," an ominous and mysterious mark that holds deeper meaning. Faced with the choice of where her loyalties lie, Sakura confronts her fate and a world torn by the divide between youko and humanity.