The alumni association that has been gone for a long time, Sung-hyeon reunited with her first love, Jin-hee, in an atmosphere of trying to spend a hot night with her. Sincerely, Sung-hyun arrives in a cab and realizes that at some point he is returning to the morning of the alumni reunion. Sung-Hyun decides to mobilize all the ways to take Jin-hee in a day that repeats as much as one night’s failure.