Cha Ju-hyeok works at a bank and has been married to Seo U-jin for five years. When a strange incident happens one day, Ju-hyeok makes a decision that impacts his life and those around him in unexpected ways. Suddenly, the life he had with U-jin and his best friend, Yun Jong-hu, is gone, and he is leading a very different life. How will his first love, Lee Hye-won, factor into his new life? And will it be possible to get his old life back?