Arifureta Shokugyou de Sekai Saikyou (WN) - Volume 4 Chapter 1

The most famous deed of this princess was her words to her younger brother Liu Ziye.

When he became emperor, she told him, “Although your highness and I are of different sexes, we are the children of the same father. Why can you sleep with so many different women, while I must be only with my husband? This is so unfair!”

And after the Emperor Liu Ziye heard his elder sister’s words, he ridiculously thought it made sense. So he immediately corrected his “wrong ways” and painstakingly selected thirty handsome youths for her to enjoy.

Chu Yu awoke in the princess’s body and realized that she had obtained a male harem of three thousand; should she take just one to drink, or keep all of them?

- Description from Novelupdates

“THE NEW GATE”, an online game that trapped its players and turned into a death game, was now releasing the thousands of players that had been dragged into it, thanks to the efforts of Shin, one of the most powerful players. But after having defeated the last boss and freed everyone, he was swallowed up by a strange light and found himself inside the game world 500 years in the future and unable to leave.

In a world where ancient magic has been resurrected. Atlas, an orphan from Earth, finds himself transmigrated into the body of a child and possesses the rare Void Magic. Harboring such power, he’ll walk the path of becoming stronger and stand free in the sky above all existence!The tale of the Legendary Void Walker is about to begin!The cover doesn't belong to me! The title was done by TiramisuAndCoffee!

The MC entered the body of the An family eldest son, An Ziran, an arrogant 16 years old boy who weighed 78 kg (~171-172 lbs), who only knew how to eat, play and sleep. Seeing his current body, An Ziran decided his first priority was to LOSE WEIGHT!