Wu Minghui and his younger sister Wu Jiali live in Mumian Island by their owm since their parents died in an plane accident five years ago and their elder sister works in another city. However, they are still optimistic and enjoy the school life with their friends Zeng Feng, Xu Ruixia and a transfer student from UK named Yu Lijie. With time going by, Minghui gradually realizes the secrets of Ruixia and Lijie by chance. Meanwhile, the brother-sister relationship between Minghui and Jiali changes a little.