"The sun is strong, consistent, but dangerous. The moon is exquisite, though extremely cold."

For a long time just being childhood friends, Shi Yun and Tao Bin are slowly aware of each other's feelings. These two people who are full of secrets little by little starts to open their hearts. But, among them, there is also another person, the 'swimming buddy' Fan Yang.

Both are as strong as the sun, as cold and exquisite as the moon. Shi Yun hesitated. Who will he choose?