She was his first love, his first heartbreak, and his only regret.
Celeste and Zane are childhood rivals, inheriting their rivalry from their grandparents before them. Except, the line between love and hate is thinner than either expected. When Celeste returns from college overseas, Zane asks for a chance to show her he's no longer the childish boy she grew up with.
The two date, despite the odds, and despite their grandparents' disapproval. Just as they've decided to forge ahead and get married, tragedy strikes, forcing them apart, and leading Celeste to believe Zane cheated on her with her best friend, who takes her own life after confessing.
As a result, she attempts to sabotage our (innocent) hero, who in turn brings her family's company to the brink of ruin, only for both grandparents to intervene and enforce a merger, and an arranged marriage between the two.
The two learn to be together again, and the longer they're married, the clearer it becomes that the truth the is subjective.
The two must learn to overcome their past, and build a future from the ruins.