Set in the competitive world of figure skating and the advertising industry, 'Triple' follows the intertwined lives of step-siblings and estranged spouses. Shin Ha-ru is a successful and meticulous advertising executive who unexpectedly reunites with his ex-wife, Lee Su-in, when she joins his agency. Meanwhile, Ha-ru's bubbly and determined step-sister, Lee Ha-ru, moves into the house he shares with his business partners and close friends, Jo Poong-ho and Kang Hyun-tae, while relentlessly pursuing her dream of becoming a national figure skating champion. As the household fills with conflicting romantic feelings, professional rivalries, and unresolved trauma from their shared pasts, the characters must navigate the delicate balance between their careers and their true hearts. The drama explores themes of growth, familial bonds, and the complexities of first loves that refuse to die out, all set against the backdrop of the icy skating rink and the fast-paced world of creative advertising.