Unemployed and recently dumped, Zhang Yuan unexpectedly awakens the Holy Grail system, tossing eighteen sacred cups in a row at the Guan Emperor Temple and becoming hailed by everyone as a lucky star. Bosses hire him at high salaries to bring good fortune; saving people, winning lotteries, and finding lost relatives happen one after another, and even his casual complaints frequently come true. While enjoying the adulation of the crowd and questioning his own reality, he finds himself unwittingly pulled into cases and danger. When a joke truly becomes a matter of life and death, can this sharp-tongued yet soft-hearted ordinary man still treat everything as a mere coincidence?