Yeon Ji Yeon is angered after she discovers on their third anniversary date that her boyfriend has actually been cheating on her. She rans off the restaurant and drives away as she settles her confusion. Unexpectedly, she encounters an accident on the road. She wakes up in a hospital two months later after the accident and was told by the doctor that she has amnesia. Devastated with her condition, she goes against the doctor and claims that she did not lose her memory. The doctor rather explains to her about her condition and proved to her how and why she lost her memory. She then has a talk with the car owner and decides to settle it by taking her to his home as he accomodates her sickness. She later finds out that the man who she was staying with was a member of a famous boy group called BTS. She continues her state being an amnesia girl and later gets to know BTS member Jin.