Cinderella and the Four Knights

Despite her stepmother's mistreatment, Eun Ha Won worked hard to save money for college tuition like Cinderella, but she used up the money to pay the fee for her mother's urn. Worse, she gets kicked out of her house, but she's given a special mission where she has to transform the three brothers of Haneul Group into decent human beings in three months. The oldest, Kang Hyun Min, with not only wealth but looks, is never desperate for anything. The second oldest, Kang Ji Woon, is an illegitimate child who has been living poor until he discovers his mother's diary and the fact that he's actually a conglomerate's blood. The youngest is Kang Seo Woo, who became a star as an ordinary boy with a powerful voice and talents. But he goes into a slump as people find out he's a grandson of Haneul Group's owner. Will the three brothers, who each had been leading different lives, be able to realize the true meaning of life while living together with Ha Won at Haneul Mansion?