On his 22nd birthday night, a mysterious girl named Xiao Qi appears to save Lin Yu, claiming she was entrusted by him 60 years in the future to prevent three fatal accidents. From suspicion to shock, Lin Yu discovers that Xiao Qi is a robot. As Xiao Qi protects Lin Yu and defuses crises, her programming begins to experience emotional fluctuations; Lin Yu gradually falls in love with her, only to find that Xiao Qi's chest energy core is unstable, and every time she saves him, it depletes her life. During a library collapse incident, Xiao Qi shields a stone pillar with her body, suffering severe damage and shutting down, causing Lin Yu to break down. Lin Yu spends his entire life repairing her, uncovering the truth behind the three accidents of that year. The successfully repaired Xiao Qi reboots, and the older Lin Yu sends her back to his 22-year-old self, allowing the two to stay together for a lifetime.