Soojin is born in the city of London in England. Her father, mother & older sister & brother moved to London because of business. Their father is a businessman and he had an opportunity to have a business in London as well. Their mother is a chef. They moved back to Korea when Soojin was ten-years old. Her older brother who is the oldest sibling is named, Kim Seokjin and her older sister's name is Kim Sunjin. Soojin is close to her father, mother & older brother but not her sister. Why? Her older sister became jealous of the attention she received from their parents. Her older sister always made her cry and bullied her. She destroyed Soojin's dolls and toys so her parents were angry at her older sister for being bad to Soojin. Soojin used to be a nice girl when she was young but something terrible changed her. It was her anger. Nowadays, their parents go to different countries because of work so only the siblings were left at home. Her sister continued to hate her. She would always scold or command Soojin to do stuff that she herself can do without any person's help. Like cleaning the table or even just putting lipstick. Soojin swallowed her pride when she was young and continued to do what her sister tells her but now, she has so much anger against her older sister that she became bad and exploded because of anger. 

There is only one person in the world who can control or console her... It is her older brother Seokjin who takes care of Soojin well. He was always there to protect her from their sister. Seokjin is older than their sister so she listens and stops when Seokjin is there. Soojin now became a sorrowful & bad girl. Is there another person who can control Soojin's attitude???

THE BAD WORLD: Soojin completely turned into a bad girl when she got enough of what her sister is doing to her. Their parents didn't know this because they are both busy in their field of work. Of course, they do care about their children and try to call them everyday. Soojin wanted to hit her sister even just once, just so she can make her pay for all the sorrow and pain she felt but she didn't... Why? Because the old Soojin is still there... The Soojin who smiles all the time, The Nice and Kind-hearted girl who was once was her... and lastly, the Soojin who is bright and affectionate. She was so filled with pain and sorrow all the time that is why she likes peaceful and quiet places where she can be at peace and escape from all the pain she is experiencing. The place where she can be her old self. Soojin sings her heart out at the rooftop most of the time. It's her favorite place in her school and shouts loudly everytime she wants to explode and say all the words she wants to say. Soojin throws all of her anger at the people in school. This is the reason why she became bad. The anger was taking over her. When she comes out of the house with her older brother Seokjin, she hugs her and cries everytime after being abused by her own sister. She can't manage her anger well and Seokjin is the only one who can control her. Whenever she comes home with her angry attitude, her anger weakens when she sees her older brother who she loves very much. She has some friends and they are her brother's friends. It's better to run and go away from her when she walks into the school every morning... Soojin bursts in anger everytime and will throw things here and there.

THE GOODY GOODY WORLD: Soojin is one of the top students in this world. The most intelligent student of all. The people that bad Soojin hates the most. Soojin is very warm-hearted and charming. She always greets people politely. Soojin is very honest and optimistic. The "Bad World" Soojin was shocked to see that her brother was bad on the other world then her older sister was like so calm and loving unlike their personalities in the other world. The "Goody Goody" Soojin likes to play around and go shopping with her friends. She is a popular girl in school and has fanboys around the school. This Soojin wasn't sad or hurt in this world but the "Bad Soojin" hates it that her brother is so arrogant here in the "Goody Goody" world.

PERSONALITY. {The Bad World} A very sincere, considerate and thoughtful guy who always looks at Soojin and became very concerned about her that it became his habit to follow her and he feels like he wants to take care of her. He is also kind, funny and helpful. Soojin classmate who she doesn't notice until the following incident happened and she catched him following. 

{The Goody Goody World} In the "Goody Goody" world, he became brave, self-confident,  ignorant and didn't even take a look at Soojin like he does in the other world. Soojin was surprised to see him like this so she once tried all she can to catch his attention which is like, what Xero was actually doing to her in the "Bad" world. 

MEETING. They met at Soojin's own world. He is Soojin's classmate at first. She was not paying attention at him but she once catched him awkwardly following. Soojin noticed that someone always leave a soda and a letter on her desk. She thought it was probably that guy who always would follow her and help her silently. 

INTERACTION. {The Bad World} It was obviously like this. Xero always following and helping Soojin without her noticing then Soojin always walking, throwing stuff, pushing people, felt that someone was following her and she was feeling creepy. Xero wasn't brave or confident in Soojin's own world but one day, he gathered all his courage to make friends with her. Soojin first didn't want to be friends with him but she did when she realized that it was him who was putting soda on her desk and helping her when she needs it. For example, when Soojin was about to be pranked by some students who are sick of her. There was Xero who bothered those students just so Soojin can go in the class without water pouring over her. They started to be friends and always met at the rooftop to eat or be at peace and feel the fresh air. Seokjin was first shocked that Soojin finally has a true friend when he can't protect his sister. Finally, there was someone who Soojin gets along with.

{The Goody Goody World} It became the opposite and now Soojin was the one doing all the stuff Xero used to do in the "Bad" world. Soojin is now the one helping Xero and the one who is concerned. He was feeling like Soojin has a crush on him... (So self-confident...) He began having eye-contact with her and see if Soojin would blush. The "Bad" Soojin was actually developing a crush on Xero when they started to get along in the "Bad" world.