On the surface, she is just a janitor working for a small firm. In reality, she is the secret heiress to the nation’s richest tycoon. Hiding her identity to find true love, she secretly invests $100 million to save her boyfriend’s business. But on the day of his success, he dumps her for another woman, mocking her poverty. Heartbroken, she runs into a powerful reclusive CEO who needs a fake marriage to escape an arranged union. As the Mistaken Heiress, she accepts the deal. Watch the face-slapping reversal as her ex-boyfriend discovers his 'janitor' girlfriend is the billionaire chairwoman who owns his company. True love blossoms under her secret.