Love can make two people feel close even when they're far apart, and yet without love, they may feel distant even when they're near. Just how many reasons does one need to love? Yishan and Shuyang have known each other since childhood, and though they've never confessed their feelings, they've always been in tune with one another. The strange thing is, Shuyang's father, Li Jincheng, and Yishan's father, Yi Qiang, both believe that Yishan is their own biological daughter.
During a trip, Yishan and Shuyang get lost and find themselves in the "Valley of Death". In order to survive, they save each other's lives, which deepens their feelings for one another.