Meng Zhi is an avid reader, currently reading a detective mystery novel, though she only cares about the melodramatic romance. But after the unscrupulous, ignorant, and useless author makes a chaotic round of revisions, Meng Zhi is forced to transmigrate into the story as a patch.
The plot itself remains unchanged, except that the ending has inexplicably been changed to a happy ending. Meng Zhi's mission is to help the author fix the story so that the whole book can reach a happy ending in a logical way.
After going over the plot, Meng Zhi realizes that only one thing stands in the way of a happy ending: Jiang Yan, the biggest villain in the entire book. He's the only one who gets a happy ending, of course, in a tragic ending where both the hero and heroine die.
The hero and heroine investigate cases together. Jiang Yan then conceals his identity as the Prince Regent, joins them, and guides them step by step toward identifying the emperor as the ultimate culprit. In the end, the hero and heroine borrow troops from the heroine's master and lay siege to the emperor.
Just as both sides are left badly weakened, Jiang Yan surrounds the hero, heroine, and emperor with the elite troops he's trained himself. At that moment, the poison Jiang Yan planted in the heroine takes effect, and she dies. Seeing her dead, the hero decides he can't go on living either, and takes his own life. Needless to say, the emperor is killed, and Jiang Yan becomes emperor. The imperial capital flourishes, and the people live in peace and contentment.
If the author hadn't clearly identified the hero and heroine, Meng Zhi would have thought Jiang Yan was the male lead and this was a power fantasy about a single male protagonist. So Meng Zhi decides to steal the villain's role and steer the hero and heroine toward a happy ending.
But something is very wrong:
When Meng Zhi steals the villain's final deduction, the villain is elegantly cracking sunflower seeds, paying no attention to what's happening around him.
When Meng Zhi takes a sword meant for the heroine on the villain's behalf, the villain is off to the side teasing a bird, even calling it Meng Zhi as he does.
The bird: Have you no manners?
When Meng Zhi takes a deadly poison meant for the villain, the villain disappears. In short, he shows no intention of following the plot at all.
Meng Zhi slams the table in frustration. I'm done!!!
Note: Dear readers, the male lead is not a yandere! The male lead is not a yandere!! The male lead is not a yandere!!! (Important things must be said three times. If that's not to your taste, feel free to leave.)
Theme: A hard-working heroine and a carefree male lead