Before I Could Reveal I Was the Fake Young Master, My Yandere Sister Locked Me Up

[Everyone Misinterprets Him + Multiple Heroines + Contrast + Mastermind Behind the Scenes + Love Rivals]

After transmigrating into a book twenty years ago, Gu Ci knows all too well that he's a "fake young master" who could be cast aside at any moment.

To avoid the fate of dying miserably on the streets, he acts like the frail, well-behaved little brother of the Gu family, while secretly founding the world's number-one underground organization, "Yellow Springs," and amassing a fortune worth trillions.

All he has to do is hand over the keys to his mansion when the real young master returns, take the money, and run off to live the carefree life he wants.

But on the day the real young master returns, just as Gu Ci walks to the door with his suitcase, everything takes an unexpected turn!

His aloof CEO eldest sister bolts the door shut, her gaze unreadable. "A Ci, where do you think you're going?"

His international movie-star second sister toys with a scalpel, smiling eerily. "The world outside is dangerous. You're safest in your big sister's arms."

Even the "real young master," who was supposed to be a man, has turned into an adorable girl and clings to his leg. "Big brother is mine. No one else can have him!"

Surrounded by sisters whose gazes smolder as they close in, Gu Ci trembles.

"Wait... weren't you supposed to kick me out? Why have you all turned evil?!"

When Gu Ci's secret identity as the "Underworld King" is exposed one day, his sisters get even more excited. "So my little brother is this strong? Then there's even less chance we'll let you run away!"