Goo Jun Pyo is the hot-headed leader of F4.He is the heir of Shinhwa Group, and after his father [supposedly] passes away, he inherits and begins to run the Shinhwa Group along with his mother. When he was eight,he was kidnapped by his own driver. The car crashed and plunged into a lake, and from then on Jun Pyo had been afraid of swimming. Exasperated by Jan Di's act of defiance, he makes her a target of bullying.But as time passes, he begins to admire Jan di's determination and falls in love with her.
A first, Goo Jun Pyo is portrayed as a bully and the feared leader of the elite gang, F4. He is arrogant and know one ever stood up to him until the arrival of Geum Jan Di. Ironically, Gu Jun Pyo, having never been stood up to, begins to develop feelings for her. He tries unsuccessfully to woo her as she slowly begins to spend more time with Jun Pyo and his friends. Jan Di teaches Jun Pyo that money cannot buy everything and in order to have real friends, he himself must be real or use his heart, but Gu Jun Pyo still does not understand why someone like Jan Di should dislike him. As the story progresses, Jun Pyo falls deeper in love with Jan Di and she learns how to open herself to his love as well.
Although he has competition with Yoon Ji Hoo he has also developed feelings for Jan Di. Ji Hoo is not the only one he dislikes Jun Pyo dating Jan Di. Jun Pyo's mother hates the idea and does everything she can to split the couple. Jun Pyo has a particularly bad relationship with his mother was always busy and never had time for him. He is hatred deepens when she starts to meddle in his relationship with Jan Di. His mother wants him to become a suitable heir for the Shinwa group and does not want him to be fraternizing with someone as low status as Jan Di. She even tries to set up Jun Pyo with a rich heiress.
He also has one older sister who he admires despite the fact that she always beats him up. Before Jan Di entered his life, his sister was the only one who stood up to him.