Bong Soo(Sul Kyung Gu) has been working as manager of a small bank in an apartment complex for three years. During his three years there, no, for 23 years if you count his school days, he has never been late. However, he purposely decides to skip work one day. There is only one reason. Inside a subway train that has suddenly stopped on his way to work, everyone around him reaches for their cell phones to call someone. At that moment, he realized that he does not have a single person to call. He does not know that inside the educational center across the street from the bank where he works, a 27-year-old woman Won Ju(Jeon Do Youn) is looking over to him, nourishing a small love. Bong Soo and Won Ju run into each other every day, at the Ramen restaurant, at the bank, at the bus station... Various trivial incidents occur, but Bong Soo still does not truly recognize Won Ju's presence.