Two thirteen-year-old boys were once close and were the warmest existences in each other's lives.However, when their deep friendship was questioned and discussed by classmates, rumors were quietly built between the two of them like cold walls.They had once talked about everything and began to be alienated, and their hearts that had once been closely linked slowly opened up. It was not until a sudden tragedy that one of the boys had to face the question deep in his heart that had been avoiding: Why did he choose to stay away from his closest friends?In the interweaving of memories and reality, he began to look for answers and reexamined the misunderstood but never really disappeared.