Jin Joo and Ban Do met when they were twenty and got married when they were 24.

Ban Do and Jin Joo return to the year they were 20; they are both excited to return to their college years, but that excitement turns out to be temporary; they meet at an unexpected place only to be reminded of the events that occurred that day.

Jin Joo and Ban Do think their return to 1999 is a miracle that will last only one night; they wake up the next day still stuck in 1999.

Jin Joo and Ban Do's argument is heard throughout the campus as it was broadcasted on the school radio; the students of the school begin their search to find the married couple; Nam Gil saves Jin Joo from getting hurt.

Ban Do starts to worry about Jin Joo after she gets involved with Hyun Suk; Nam Gil keeps calling Jin Joo out; he uses the leg he hurt while saving her as an excuse to see her; Jin Joo bumps into Ban Do and Seo Young at an unexpected place.

It's festival day at Hankook University; Ban Do remembers the humiliation he suffered on this day; he does whatever he can in order to prevent history from repeating itself; Jin Joo ends up entering the May Queen contest.