School days that remain as exciting memories of studying, or bullying, and running away for some. After graduation, a text message is sent to all 3rd year class 5 students, who lived their lives, to participate in the reunion. A text message from whom the sender is not known. A prize of 10 million won. Although this all sounded very suspicious, they all attended the reunion half-jokingly, where they will have to face their own past, the one they had buried in their deepest memories.