Having lost her mother at a young age, Chisato grew up with her father. She married her university classmate Mayama Yuta, who is now the heir to a large company, and was meant to lead a happy married life, but instead finds herself treated like a “housekeeper” by both Yuta and her parents-in-law. Then, one day, she witnesses her husband walking affectionately with a young woman, Mitsui Runa. When finding out he betrayed her, she explodes with anger at Yuta, but a struggle with Yuta leads to her getting hit by a car. When Chisato awakens in the hospital, she discovers she’s actually been reincarnated as Runa, and thus, she vows to dedicate her new life to getting revenge on Yuta.
Le Jun Kai is a man who lives his life trying to foster a hatred for his enemy and devising ways to seek revenge for his former lover and unborn child. He decides to marry his enemy's daughter, Le Yi, and then proceeds to mistreat her and make her life as miserable as possible, but yet she bears this without retaliation. A problem arises when Le Jun Kai begins to realize he might have feelings for Le Ye Zi.
Sakuraba Haruma's childhood friend Inukai Shuji was a cut above him in every way imaginable, living out the glamorous life bestowed upon him. Haruma, an unassuming salaryman, has lived his every day clutching onto his inferiority complex, existing only in Shuji's shadow. One day, Haruma coincidentally meets Shuji's wife, Inukai Reika, who Haruma has always secretly admired since his high school days. With feelings of envy, jealousy, and more, a "secret" is born from Haruma's repetitive days.
