The house burns down, the family splits and years later Mei gets a job as a housekeeper in order to extract vengeance. Mei is forbidden from leaving the first floor.
Mei is caught by someone. He uses threats to reveal the secret of Mei's identity to control Mei. Her controller offers to reveal the full truth about the fire.
Mei drives her boss around but her true identity remains hidden. An old blog is republished identifying the author as M. Who is M is going viral. A family confrontation ensues.
Mei's father is getting a divorce. Mei's mother is owed an apology. Mei's father decides to support her stepmother disappointing Mei. Someone attacks the stepmother, exposing everything. The someone is revealed.