An unexpected call with news of the deterioration in the condition of everyone's beloved mentor, Professor Yoon, makes Jong Yoon remember the turbulent days of his student youth in the early 80s, and relive the joy of friendship and love emerging against the backdrop of civil unrest in Seoul. The house of Mira's parents briefly brings together two girls and two boys. Some of them have experienced personal dramas, others are just about to face them. The years fly by. Chung Yun seeks solace in world literature, her lover Myung Se, a successful photographer, travels around the world in search of more and more hugs as a symbol of unity. All these years, away from each other, they ask a question that cannot be answered: why were they not there at the moment when their friends - Dan and Miru - needed their support most? Just being close, loving and moving on is so simple, but an insurmountable feeling of guilt, like a centrifugal force, does not allow them to be together