Lee seunghyun, Lee chaerin,Kwon jiyong & Dong youngbae are childhood bestfriends they grow together in los angeles even if they are korean. They are really close to each other even if their parents,brothers and sisters a close to each other too. They love music, for them if there's no music there's no life, they even made a group called "4-D" Means Four dreamers who are dreaming together to become famous all around the world and no one can separate them... But is that really true that no one can separate them? We'll see...
 

Lee chaerin - 12 years old, in her young age she is already known as the "Bad girl" in their school because of her strong and cold    appearance but for the three(seungri,jiyong,youngbae) she is not really the girl that the others known her to be, but a cute and playful girl   who loves to eat ice cream but sometimes she is so boyish and cool... She is the main vocalist of the band, she have a very strong voice  and she knew how to own the entire stage. She can dance,sing,rap and play instruments, other than that she is also good at paintings and drawings. She loves to stick at jiyong's side every time she is bored and whenever she wanted to.
 

Lee seunghyun - 12 years old, who have a little crush on chaerin. He found her cute and cool but when they are together they just fight and fight even if it's just a little thing to argue for. He is the drummer of the band, he is really a pro when it comes to drums. He is good at dancing. He knows how to make people laught.He is energetic and playful but he can be annoyinng sometimes and say words that can cause troubles that is his friends worrying about him. He is also a photographer, he loves to take pictures of people and sceneries and he also love to record a video of him and his friends.

Dong youngbae - 15 years old, The most calm and hardworking in the group. He is the pianist in the band and girls just melts whenever they hear his soft angelic voice. He can sing,dance and rap. He is good at sports, he joined soccer team. He is good at dancing too, he can master all the steps in one blink of an eye. His best friend jiyong are the only one who understand him,he knows all of his attitudes.

Kwon jiyong - 15 years old, the guitarist and the leader of the band, he know how to manage and take care of s well. He always protects chaerin, he don't even know why he do it and he always love to . He really love music and fashion is his life. He can rap,sing,dance and known to be the youngest composer. He is a perfectionist. He always bring his favorite guitar with him and treat it like a baby.