Goo Jae-hee lives in the United States and one day sees a track and field competition on TV, and becomes attracted to one of the high jump competitors, Kang Tae-joon. She begins to idolize the young athlete and eventually transfers to Korea to attend the same school that Tae-joon attends after he suffers an accident that could potentially end his career. There is a catch, however: Tae-joon attends an all-boys high school and Jae-hee must disguise herself as a boy to enter.
Despite a 200-year-old treaty between humans and vampires, both races still don't get along. Amidst the looming tension, Jung Jae Min, a posh yet kindhearted high school student, quickly falls for the mysterious new girl Baek Ma Ri. But can Ma Ri conceal her true vampire identity and give love an honest chance? If these star-crossed lovers can find the courage to make the leap, Jae Min and Ma Ri may just be the key to a final resolution between humans and vampires...
Park Jung-Woo is a prosecutor at Seoul Central District Prosecutors' Office. One day, he wakes up and finds himself in locked up at the police station. He has temporary amnesia. Park Jung-Woo is falsely accused and is sentenced to death. He must struggle to prove his innocence.
Kim Seo-Jin is a man who is driven only to achieve success in his life. Thanks to his efforts, he is the youngest executive at his company. His life is perfect, with his beautiful violinist wife Kang Hyun-Chae and a daughter. His wonderful life comes to a halt when his young daughter is kidnapped. He falls deep into despair. To change the past, when his daughter was kidnapped, he contacts Han Ae-Ri approximately one month in the past.
Han Ae-Ri has busy days with her studies and working a part-time job to make enough money to pay for her sick mother's operation. One day, her mother suddenly goes missing. Han Ae-Ri falls into despair, when Kim Seo-Jin from the future contacts her.
When they were children, Yoon Na Moo and Gil Nak Won were each others first love. They are forced to break apart when Na Moo's father Yoon Hee Jae, a psychopath serial killer, murders Nak Won's parents. 9 years later Yoon Na Moo is known as Chae Do Jin, a passionate and kind rookie detective wishing to atone for his father's sins. And Gil Nak Won is now Han Jae Yi, an aspiring actress following in the footsteps of her mother. She suffers from a panic disorder but still has a good outlook on life. However, the sadness of their past comes to light again and their short-lived encounter is over before it began. Another three years on, Jae Yi has become a popular actress and Do Jin is now an experienced detective. When their fate becomes connected once more, will their love prove to be stronger than their past?
Choi Kang-Woo is a former detective, but he now works as a veteran insurance investigator. He leads a team that attempts to reveal insurance fraud cases.
Go Nam-soon, a young boy, constantly gets bullied by a group in his class. Later, one of his old rivals joins his school. Eventually, they are able to sort out their differences.