In the waiting hall of the airport, he seriously asked her to wait for him for four years, and they would never be separated again in the future. But 5 years have passed, 5 years have passed since he left abroad, and she has been waiting, even though it was known a year ago that his home had moved away when he went abroad, and even though it had been 4 years since there was any news about him. She is still waiting, because they have an agreement, and memories are the support for her to keep the agreement.
Five years ago, she was a sophomore, he was a senior high school graduate, and she was his tutor. Love came so suddenly, which made people excited and helpless, because it was a love that was not allowed.
When the two meet again five years later, will he still remember the agreement she has always kept? Will love continue? Can his promise to her be fulfilled?