Secret Garden tells the improbable love story of Kim Joo-won, an arrogant and eccentric CEO of a luxury department store, and Gil Ra-im, a fierce, hardworking stuntwoman whose beauty and strength command respect in a male-dominated field. Their worlds collide when Joo-won mistakes Ra-im for actress Park Chae-rin, sparking a persistent and complicated pursuit by the wealthy heir despite their vast social differences. Their complicated lives take a fantastical turn when they visit a mysterious restaurant in Jeju Island and are given strange medicinal liquors by the eccentric owner. The following morning, they wake up to find that their souls have been swapped into each other's bodies. Forced to live each other's lives, they must navigate the challenges of the high-society corporate world and the physically punishing realm of stunt work while trying to reverse the curse. As they swap back and forth unpredictably throughout the series, Joo-won and Ra-im develop a profound understanding of one another's deeply buried traumas, family pressures, and insecurities. They must confront fierce opposition from Joo-won's imperious mother and internal demons before they can find a way to true happiness, testing the limits of identity, class divide, and selfless love.