25 years ago, the Haesung Group lost their granddaughter Choi Eun Seok. The girl was found and raised by Seo Tae Soo as one of his twin daughters, Seo Ji Ahn and Seo Ji Soo, They grew up rich, but their father was bankrupt, and they had to experience the hard life of a dirt spoon. Ji Ahn is now a contract worker at Haesung Group who would do anything for a job, while Ji Soo is an air-headed part-timer who has a one-sided crush on Sun Woo Hyuk. Unknown to her that Woo Hyuk was in love with Ji Ahn in high school. Choi Do Kyung is Haesung Group's oldest grandson. He is gentle and kind, but being too good yet still single makes his employees spread weird rumors about him. He meets Ji Ahn in a car accident and comes to know her sad situation, but his biggest shock is when his mother reveals that his lost sister is Ji Ahn.