Ban Ji Eum has an extraordinary ability: she can remember the memories of all her past lives. Repeating her reincarnation for nearly a thousand years, Ban Ji Eum has been living her lives diligently. After her previous life is cut short by a tragic accident, she sets out to reconnect with the people of her past life in her current one, and decides to find a man named Moon Seo Ha, whom she met in her 18th life. Will memories of her 18th life sabotage romance in her 19th? Or will love endure across different lives? On the other side, there is also Yoon Cho Won, a landscape architect and the younger sister of Yoon Joo Won, whose life collapsed after her older sister's death. She is courageous and kind, even after facing the death of her beloved sister, but she struggles to maintain her brightness. When Yoon Cho Won meets Ban Ji Eum by chance and sees her older sister in her, she wonders about Ban Ji Eum’s identity. Then there's Ha Do Yoon, Moon Seo Ha’s secretary and best friend since childhood. Although they come from completely different backgrounds, Ha Do Yoon feels some kind of affinity for him.