After the will of the late Chairman Kim has opened, all the property was transferred under the illegitimate heir, Kim Myungsoo which angered the legitimate heir, Kim Joonmyeon, who thought that he was supposed to own all his father’s property. The very next day, Kim Myungsoo was missing.

Jung Soojung, the Kim’s brothers’ cousin, who was always under Myungsoo’s care, also joined force to find her cousin. That’s when she came to the CN Blue Club, the underground spy club. Coincidentally, Kang Minhyuk, her ex-boyfriend, was the one who was responsible for her case.

When two past lovers came together, there’s no doubt that they will reminisce the old times, their good memories back then.

Fire that was once died out will light up again if there’s wind passing by. So, what if the two past lovers got closed with each other once again, will their love light that once died out lit once again?