No-eul has never left her room for three years because of depression and anthropophobia; since their father has to go away for a long time because of work, Ha-neul has to take care of her sister.

Seoul, 2008. On a bus heading to their hometown, fate brings Eun-ho and Jeong-won together, sparking an unlikely friendship. While battling a bustling and weary city life, they find themselves sharing lofty dreams and a love that comes to feel extraordinary. But, eventually, the harsh realities of life lead them to part ways. Over a decade after the separation, the two unexpectedly reunite on a flight back to Korea, where they reflect on their lost time.