Twin sisters Yoo Mi Ji and Yoo Mi Rae differ in everything except their faces. Yoo Mi Ji, the younger of the twins, has ended her short heyday as a promising track and field athlete and is currently living a free-spirited life. On the other hand, the older sister of the twins, Yoo Mi Rae, who has been walking the path of the elite since her school days, is a perfectionist working at a public corporation. The twins, physically identical but leading starkly different lives, embark on a bold charade, switching lives for some undisclosed reason.
Lee Ho Su is a lawyer at a large law firm with a tall appearance and a seemingly carefree attitude. He may look like a noble swan with no external flaws, but he works harder than others to live an ordinary life, and this is because he has been living a different life than before after experiencing something in the past. As a result, he lives a calm life without showing his true feelings, but one day, an unexpected encounter occurs that sends waves through Ho Su's heart.