When Jinpai repairman Li Jun goes on a home call to fix a water heater, he insists on only replacing parts that are truly broken, but watches as his colleague Liu Waizui scares an elderly person into spending extra unjustified money. Boss Zhang requires everyone to exaggerate malfunctions, replacing assemblies rather than ever repairing parts, and Li Jun is driven out of the company after refusing. He rents a basement garage to open a shop, bringing along apprentice Xiao Zhou and later the awakened Old Chen, slowly winning back the trust of the neighborhood with transparent quotes, original parts, and complete records. But his former employer, unwilling to lose business, successively creates misunderstandings and secretly sabotages inspections. Li Jun holds the bottom line of only repairing what is broken and not replacing what is expensive, turning his small shop into a reliable repair establishment and industry benchmark for everyone.