A couple who pretend to be newlyweds, find themselves developing genuine feelings for each other as they navigate their fake marriage.

After 10 years in the US, Hu-young returns to Korea and meets his first love, Hong-ju, at a café by chance. Just as the window into which Peter Pan flew happened to be Wendy's room. Just as the prince happened to find Cinderella's glass shoes. As if nothing had changed in the past 10 years, Hu-young becomes clumsier only in front of Hong-ju. It’s like going back to the age of 19 when he met his first love, Hong-ju. Hu-young and Hong-ju’s days, which have faded a little, begin to turn into vivid rainbow colors again.