The kingdom of Kouka is blessed with a beautiful princess whose childlike innocence charms all who come across her. Named Yona, she has grown up sheltered in the royal palace, shielded from any danger that may befall her. However, all good things must come to an end. Yona's perfect world comes crashing down when a heinous act of treason threatens to erase all that she holds dear, including her birthright as the princess of Kouka. Left with no one to trust but her childhood friend and loyal bodyguard Son Hak, she is forced to flee the palace. Faced with the perils of surviving in the wild with a target on her back, Yona realizes that her kingdom is no longer the safe haven it once was. Free from the shackles of naivety, Yona vows to do everything in her power to become strong enough to crush her enemies. With Hak by her side, she must piece together the remains of an ancient legend that might be the key to reclaiming her kingdom from those who conspired to steal it from her. Since Yona is the only princess of a grand kingdom, she has been raised with great care by her doting father and protected by her childhood friend/guard Son Haku and others. However, her fate changes on her 16th birthday, when her beloved cousin Suwon murders her father to claim the throne. She flees the castle to Son Haku's hometown and begins her new life.