Lin Xiao has always wanted to find his own sun, hoping that someone can let him see the warmth and beauty of this world... "Brother Xiaoxiao, can I be your sun?" 16-Year-old Lu Yang said seriously as he looked at his elder brother who was as tall as himself. Lin Xiao smiled and touched his head, thinking that the big boy was joking with him, and said, "Okay, when Xiaoyang grows up and becomes an adult, my brother will let you be my sun." From then on, Lu Yang wanted to be an adult, Lin Xiao's sun... "I'm sorry Xiaoyang, you shouldn't be my sun..." When Lu Yang finally became an adult, he thought he could be Lin Xiao's sun, but why... Brother Xiaoxiao would refuse! What will Liuyang do? Does Lin Xiao really think that Lu Yang is not his sun?