The film tells the story of a Korean boy, Junhao (Lee Joon-gi), who silently protects his beloved girlfriend, Xiaoyou (Zhou Dongyu), in an invisible way and helps her restart her life and love. This cross-border "hand-in-hand" not only takes place in the modern city of Shanghai, but also goes as far as Sicily, Italy, which is full of beautiful legends, to stage a touching love story that transcends national borders and regions.