Princess Yona is the only daughter of King Il, the pacifistic ruler of the Kouka Kingdom. Yona worries about her red hair moments before the arrival of her older cousin and love interest Soo-Won. A flashback reveals that Soo-Won gave Yona a pear and slept by her side for one night to help her cope with her mother's death. The next day, Yona's childhood friend and bodyguard Son Hak practices mounted archery with Soo-Won, who later shows Yona how to ride a horse. Disapproving of Yona yearning to be with Soo-Won, King Il wants to decide his own successor to the kingdom. She later runs into Soo-Won and confesses to him, but he only sees her as a sister rather than a lover. Five days later, Yona celebrates her sixteenth birthday, and a party is held in the castle. Soo-Won gives Yona a hairpin as a gift, telling her that her crimson hair is like the color of the sky at dawn. At night when it rains, Yona witnesses Soo-Won stabbing King Il in the chest.