It Seems That I've Slipped Into a Different World. Also, My Gender Has Changed. - Chapter 11: Abundant Learning, during a Castle Tour (Part 2)

After reincarnating as Zhou Xuanji, the prince of an empire, he thought that he would be able to live a worry-free life of luxury. He did not expect to be involved in a rivalry with the Empress herself, who forced him to escape from the palace.

Chen Rui, an otaku from earth, is reborn into a human body in another world, who falls into the legendary evil, brutal world of the devil called Mozu where humans are treated as food. He has to survive while facing horrors of the devil, violent dragons and a variety of power enemies depending on a strange super system chip and his wits. Surrounded by Devil’s beauties such as black-bellied lolita princess, cold queens, violent dragons, charming poisonous devils …

Wanting to live in the Devil’s world is hard! Wanting to live in the Devil’s world as a human is harder! Wanting a human to be the devil’s son-in-law is hardest!

Let us see how a small otaku uses power and strategy step by step starting from an ordinary human to writing a legend as the devil’s greatest son-in-law.

- Description from Novelupdates

Gu Mingxi and Pang Qian were next-door neighbors, classmates, and deskmates. From year-to-year, even when the class seating was rearranged, they would still be deskmates. They grew up together like a pair of brother and sisters despite having different parents; if it was someone else, then their parents would probably have already arranged their wedding. However, Gu Mingxi was different.