A bottle of water witnessed the beginning of their "bad relationship": the embarrassment when they first met, the surprise when they met again, the ambiguity when they got to know each other, the heartbreak when they parted, and the confusion when they reunited... She was timid in everything, but she was willing to be brave for him once; he was fearless, but hesitated when facing her. Is this bottle of water a red line from the sky or is it the beginning of mutual torture? Many years later, Xu Tong has been thinking about this issue, but the word fate is still elusive...