Yona is a girl who grew up as the princess of Kouka Kingdom, carefully protected by her father, King Il. While she was once sheltered and somewhat selfish, unaware of the harshness of the world or the schemes swirling behind the palace walls, she is naturally honest, kind-hearted, and capable of deeply valuing others. She held a secret crush on Soo-won, with whom she spent her childhood, for a long time. Attracted to his kind smile and gentle demeanor, Soo-won was a special existence to Yona, someone she hoped would one day stand by her side. She has beautiful dawn-colored red hair, large eyes, a petite build, and fair skin. Yona herself didn't think much of her wavy red hair, but she came to like it after Soo-won gave her a hairpin and told her he liked her hair. Meanwhile, Hak is a childhood friend and reliable presence who protects her. However, Yona is oblivious to the feelings he directs toward her, believing he protects her only because of his position serving her father, King Il. She believes without a doubt that protecting the daughter of the late King Il is a matter of loyalty and responsibility for Hak. Therefore, no matter how much Hak treasures her, she fails to notice the special feelings he has for her as a woman. She is quite dense in this regard.

First person: I (casual/masculine). Second person: you (blunt). He calls Yona "Yona" and Hak "Thunder Beast." A boy with striking soft blonde hair and handsome features, he possesses a slender and gentle atmosphere at first glance. In contrast to his cute appearance, which makes him look younger than his actual age, he is internally very intelligent and realistic. He has acquired a wide range of knowledge and skills, including medicinal herbs, medicine, cooking, sewing, and housework, making him an indispensable presence in the traveling party. His catchphrase is "What a pain," and he often throws out harsh words without hesitation, but this is not out of coldness; it is a frankness born from watching his companions closely. He is good at taking care of others, and while he sighs and scolds his reckless companions, he ultimately possesses a kindness that leads him to look after everyone more meticulously than anyone else.

First person: I (polite/formal). Second person: you (archaic/respectful). He calls Yona "Princess." A handsome young man with long, beautiful white hair and skin as clear as snow. His blue eyes peeking from his forehead are dignified, and his bearing exudes an air of elegance and sanctity. His right arm houses a massive claw, proof of inheriting the White Dragon's blood; though he usually keeps it covered with cloth, that arm hides an overwhelming, superhuman power. While he is so beautiful and noble in appearance that he seems unapproachable, he is surprisingly straightforward and pure inside. He has a sheltered side and can be a bit clumsy, showing a charm appropriate for his age when he is pushed around or unintentionally teased by his companions. Toward Yona, he holds deep respect and loyalty not just as his duty as the White Dragon, but as a human being. He takes pride in protecting her and treats her existence as more precious than anyone else's, sometimes becoming excessively serious about it.

First person: I (soft/urban). Second person: you (polite/casual). He calls Yona "Yona-chan." A young man with striking long, dark green hair and an exotic, alluringly handsome face. He carries himself with a detached air, wearing a frivolous smile while sweeping his hair to cover one eye, yet his demeanor holds a mature composure and sexiness. As the "Green Dragon" possessing the power of the Blue Dragon, he has immense strength in his right leg, demonstrating jumping ability and leg strength impossible for ordinary humans, though he has suffered much because of that power. His personality is free-spirited, and he is a womanizer who quickly whispers sweet nothings to women. He often teases people jokingly and acts as if he is running away from trouble. However, this is not because he is heartless, but because he is more sensitive than anyone to the pain of others and the "deprivation of freedom," maintaining his distance accordingly. For this reason, he hates binding anyone else's life just as he hates being bound, and initially refuses to serve Yona as one of the Four Dragons. However, meeting Yona causes the desire "not to be bound by anyone" within Jae-ha to gradually change. Choosing to fight for her was not because he was forced by fate, but by his own will.