She has a silent and innocent personality and is mostly ignored by the people around her. She tends to make fun of her quite uninteresting character by imagining that she has this ethereal skill of being stealth. Indeed, except for the fact that she is visually attractive, there isn’t much to notice about her at all. She is quite stout, standing at a mere height of a hundred and sixty-three centimeters which adds to the multiple other traits that makes her unnoticeable. She is silent and will not talk if she isn’t asked for or if it isn’t necessary. She is usually shy and will just be contented to sit at one corner and observe her environment.

Since Yoonah is mostly silent, she is a very good listener. Whenever her friends have problems, she is more than willing to listen to them. Though don’t expect her to give you some useful pieces of advice because she, herself, is very much naïve and innocent about the real word. Amusingly, she tends to view things in a different, kind-of childish, manner which makes her brothers so amused about her.

All her life Yoonah is guarded by her five older brothers and her strict father, which led to her can’t-do-anything-on-my-own personality. She is very dependent and will need someone to do things for her such as washing her clothes and ironing them, cleaning her stuffs and her room, tying her hair and plenty of other simple chores that a girl can usually do. But her princess-like capabilities, which apparently are very limited,  were expanded and improved during her trainee years. Rather than going home each day after training, she choose to stay on the dormitories with the other trainees. She decided that this is what's best for her, especially that she is not getting any younger. She needs to learn on how to live a normal life without all the maids ready to do the chores for her.

"I'm never perfect, but I strive hard to be the best."—says Yoonah every time she receives judgmental criticisms. Above all things in the world she hates being judge without a concrete basis. She hates being misunderstood. Because she's always shy, silent and afraid to mingle with others, most people will see her as someone dull and spoiled, which is completely opposite to what she really is.  One thing why she hasn't got plenty of friends is because she's rich and kids her age, especially boys, are all afraid of her dad and brothers. Though she is embarrassed to admit it, Yoonah never had any boyfriend since birth. She's not allowed to do have one actually and she's afraid to have one also.

Of course, Yoonah has a clumsy side too even though she's always graceful and careful. This very special moment happens whenever her crush is around her. She's really obvious you know, because she will keep on fanning herself using her hands even though the A/C is on full temperature. She will gradually trip on her heels even though she's already used at using them. She will be very uncomfortable, shifting from this position to another, and will constantly fix her hair or pull her clothes, pretending that she's busy. That's how obvious she is whenever her crush is near, that's why her group mates easily senses her liking which lead into constant teasing and nagging when they reach their dormitories. 

Fun, bubbly, childish, silent, shy, elegant, mischievous; those are the perfect words to describe our resident princess. 

Unfortunately, a few days after her very birth, her wonderful mother passed away. A simple fever after giving birth was the cause of her dear mother’s death. That explains why Catherine has no memories of her late mom, and all that's left to her were mere photographs and stories told by her father and her brothers.

Even without a mom, she was raised alone by her father and the maids of their mansion. She was then treated like a princess and all luxury was in her, both material and emotional. Her father considers her as an angel, gift by the heavens since out of his six children, she was the only girl.

All her childhood days were spent in America in which she lived like a normal American girl. She got accustomed of the American culture and was never educated about the Korean living. 

After seven years or so, her father's business demands on moving to another country once again, her eldest brothers are about to go to college that time and so their needs demand a permanent place to stay. Catherine was also growing up and constant traveling without a mother taking care of her will risk the proper growth of the child. So, her father ended up sending her, along with her two older brothers, to his parents in Korea while her three elder brothers were moved in New York to finish their studies.

Her father would constantly cross countries, visiting his children, making sure that they are all fine and are studying well. Though he is undeniably strict towards his children, he loves them truly and tries his very best to fill the empty spaces that his late wife left.

Living in Korea, Catherine, now called Yoonah, her Korean name, never imagined that her life will be mischievous, yet difficult. Mischievous; because she never knew that her paternal grandparents are both very playful and funny. Difficult; because she has to conquer lots of things including language barrier. 

Of all things in the world, Yoonah is very fond of cooking. She loves to bake pastries and make pastas for her older brother—in which she learned to call ‘oppa’—Michael. Among the five boys, Michael is the food lover which explains why he was fat during his toddler years and because of that he loves to eat Yoonah’s cooking. While Yoonah cooks at the kitchen, she also sings for she believes that her dish will be more delicious if she does so. Her grandma noticed that she had talents in singing so she recommended to her father to enroll her in a music class. Her father agreed of course for he only wanted what’s best for his daughter, the problem is, Yoonah was barely eleven and is not very fluent with the Korean language yet, so he hired a special tutor who will teach her daughter not just how to sing but also the Korean language.

Rather than her singing talents, Yoonah is also well oriented in other fields of music. She learned how to play the piano when she was five, the flute when she was seven and the violin when she was ten. She also learned how to play the cello with her home school instructor. And yes, that’s how isolated she is from the social world, she was home schooled all her life and was only exposed to socialization while she was training. She learned how to dance during her trainee years, how to act and how to professionally face the crowd as well.