Eighteen year-old Tae-hoon and Mi-jung have been going out for 100 days. During winter break they decide to take a trip to the beach to celebrate their anniversary. When they are back home after a few days, they have to confront a harsh situation – Mi-jung’s parents don’t allow them to see each other until they become college students. Tae-hoon struggles to keep their love and wanders around Mi-jung but she is eventually changed and avoids him as her parents wish. Winter turns to spring, and Tae-hoon and Mi-jung both turn nineteen.

In the spring of 1999, a group of old friends gather to celebrate their 20 year reunion. Among the group is Yeong-ho, a cold, unhappy man, whose demeanor puts a damper on the festivities. The seriousness of Yeong-ho's depression becomes apparent when he climbs a railroad bridge and looks like he might jump. At this crucial moment, memories of seven crucial episodes from Yeong-ho's past flood his mind.

Facing financial uncertainty and entering middle age, a married couple in their early thirties contemplate whether it's the right time to have their first baby.