Story follows people, including Ji Wook, who escape into dreams to forget the pain of reality. Ji Wook is a detective with excellent memory abilities.

Oh Eun Soo is a university student. Her mother has divorced twice and Oh Eun Soo learns that her mother will marry again. Oh Eun Soo isn't happy about her mother's third marriage.

In 2008, Hyun Soo and Seung Yun meet as first year students at their university's library. They join the chorus club together and build good memories together for a year. 10 years later, they meet again on the subway.