After Sun-Jae's (Ryu Si-Won) father died his mother Jang Myung-Ja (Lee Kyung-Jin) married Lee Jung-Choon (Lee Jung-Kil), who worked as an executive at Victory Records. Sun-Jae was disturbed by the whole situation. He believed his mother may have had an affair with his step-dad in the past. Furthermore, Sun-Jae also felt that his new siblings, Min-Chul (Lee Byung-Hun)& Min-Ji (Shin Min-A) despised him and their new mother. His new step-brother, is also an executive at Victory Records.  Yun-Soo (Choi Ji-Woo) and Se-Na (Lee Jung-Hyun) grew up together in a orphanage. They are not related, but relied on each other like real sisters. When Yun-Soo became of age to leave the orphanage, Yun-Soo promised Se-Na that she would meet her in Seoul, but an unexpected accident prevented her from fulfilling her promise.  Later they happened to meet again, but Se-Na still held resentment towards Yun-Soo. Yun-Soo worked at Victory Records, as a part-time employee, to earn money for her college tuition. Se-Na dreamed of becoming a singer, so she became a trainee at Victory Records. To make Se-Na's dream come true, Yun-Soo worked in Min-Chul's home to supervise his trouble-maker younger sister Min-Ji. As a condition for her work, Yun-Soo made Min-Chul promise to support Se-Na's music career.  Min-Chul is a competent and charismatic figure, but inside he feels loneliness. Min-Chul and Yun-Soo soon started to develope feelings for each other. Meanwhile, step-brother Sun-Jae was studying in medical school. Sun-Jae is a very gentle and pure person. He also carries a complex, because he was the son of a mistress and his siblings, Min-Chul and Min-Ji, looked down on him. Sun-Jae wanted to pursue music as well, but his step-father strongly opposed this idea. Nevertheless, Sun-Jae named himself Zero and introduced his music through the internet. Sun-Jae also came to love Yun-Soo.  Because of shocking past transgression committed by their father, Victory Records suddenly goes bankrupt and SuWatch drama online for free.