Lee HyeMin and Lee MinHye are twins. Minhye is the weak twin because she inherited her mothers' asthma. When they were 6 yrs. old, their parents decided to divorce because of financial problems. Their mother took MinHye,then their father took HyeMin. They made a promise that they will meet again after 10 years in their old house.  They met again,and dreamed to be an idol. They love B1A4,and they have different bias's. MinHye will get in the audition,leaving HyeMin behind. Then suddenly she will fall in love with her sisters' bias. Her sister will find out,then starts the war.