One day, Pi Ya Nuo rescued mob boss Du Zi Feng and his sister from danger, not knowing her action would cause her secret life to be exposed. She never had any close friend because no one must discover that she is a woman living as a man until her 26th birthday or, according to the fortune teller, bad things would happen. However, one thing leads to another, she and Du Zi Feng become sworn brothers. With him bend on knowing everything about her, can she make it until her 26th birthday? How would he react when he discovers her big secret?