One day, Kwang-soo, who followed his late mother's footsteps, promises to travel with his friend Seung-hwan. However, he finds an application for Taejong's father's admission to an AIDS clinic, and his father orders him to visit his mother's grave together for the last time. Kwang-soo breaks his promise with Seung-hwan and follows his father. Kwang-soo, who was shouting in front of the oxygen, sees his mother's fantasy and feels that he was not a vocalist but an onlooker. Realizing that he was in love with a Buddhist monk, Kwang-soo leaves his sick father behind him and goes to Seung-hwan late into the night and tells him to go on a 'tomorrow' train trip.