
Lee Mi-do as Kim Mi-ja, Mi-young's second oldest sister.Han Kyu as Kim Mi-sook, Mi-young's oldest sister.Park Hee-von as Jeon Ji-yeon, Mi-young's co-worker and roommate who later becomes Yong's girlfriend.Na Young-hee as Lee Gun's stepmother and Lee Yong's mother.Choi Woo-shik as Lee Yong, Lee Gun's half-brother.Park Won-sook as Chairwoman Wang, Lee Gun's grandmother.She is the long-lost biological sister of Daniel Pitt. A sudden callback has her choosing ballet over Gun one more time, but when she comes back for good, she finds drastic changes in Gun's life. But when she fails to get a lead part, Se-ra comes back to Korea to stay with Gun. She has been with Gun for 6 years, delaying any plans of marriage for her career. She is a ballerina in New York City with a surprisingly no-nonsense attitude. He is the biological brother of Kang Se-ra. Constantly worrying about her, Daniel begins to realize that what he feels towards Mi-young is something more than protectiveness. From then on, he becomes her Daddy-Long-Legs, encouraging her when she is down and coming to her rescue when she needs help.

He meets Mi-young by accident, and is intrigued by her kindness. Choi Jin-hyuk as Daniel Pitt/Kim Tae-hoĪn internationally famous Korean-American designer whose single goal is finding his long-lost biological sister.When an accidental one-night stand gets her pregnant, her plain and insignificant existence changes as Lee Gun enters her life.

While she lacks self-confidence, Mi-young always sees the best in people and upholds a quiet strength. Because of her timid and kind-to-a-fault nature, she cannot bear to turn down a request from anyone and is nicknamed the 'post-it girl,' someone who is necessary but unimportant. She has no wealthy family, prestigious education, or much beauty, but rather comes from a small island where her mom owns a small restaurant.

The wealthy heir to a large hair product company with a trademark maniacal laugh. When Mi Young finds out afterwards that she is pregnant, what will become of them? And will Kang Se Ra (Wang Ji-won) and Daniel (Choi Jin Hyuk) just stand by and let Gun and Mi Young deal with the situation in their own way? Cast Main Kim Mi Young goes into the wrong hotel room because the hotel door number accidentally changes, and the door is propped open by the mischief-making drugged liquid makers. When the two cross paths one night after separately having drank a drugged liquid a comedy of errors occurs. Kim Mi Young (Jang Nara) is an average-looking secretary in a law firm who earned the nickname “Post-It” for her inability to say no to her colleagues who dump work on her. Lee Gun (Jang Hyuk) is the successor to a large company run by his family.
