It has been 3 years since he first came to Seoul and 3 years since he knows his one and only bestfriend which is means it has been 3 years since he last had a girlfriend. 

"What is your wish this year, Dae?"

"I want to date someone."

"I want to date someone too!"

"Who?"

It has been 3 years since he last felt regrets about something and he finally realises, relationship is not everything-- it's friendship.