Isekai Kaeri no Ossan wa, Fusei Sukiru de Fathercon Musume-tachi o Tororori ni - Chapter 26: Safe Zone

To save the hopeless Dark Fantasy World, I held back my tears and destroyed the world, then killed the Demon King and returned.

Now, I’m trying to save the world using the ‘System’ I gained as the ‘Regressor’s Privilege’… but the Main Heroines have also awakened their memories of the previous timeline.

God damnit.

“In order to survive the future great war, we must take drastic measures. We need to summon warriors and train them before time runs out.”Thus, millions of earthlings were reincarnated in an alien, medieval world governed by swords and magic to save its prophesied doom.Among those individuals, one's situation inexplicably deviated from the others.Thrust into a rotting house in a ghostly body, Adam found himself bound to a wailing baby. With a heavily damaged soul and the snarky remarks of a system, he began his years-long quest to recover his body.Armed with his mind, he'll educate the baby and slowly watch him turn into a good youth. However, he would have to make a choice: suffer as a ghost until he finds an alternative that might not exist, or possess his body and reincarnate.He was far from imagining how dangerous this world full of possibilities could be, prompting him to question everything he knew... Including himself and this world's intentionally blurred history.

"I hope my wife liked the arrangements... for the wedding night."

Xia Zhijun got the title ‘study god’ after scoring first place in the whole city. He’s the model of a good student in a teacher’s eyes: good grades, good manners, and quiet. When he wasn’t smiling, his entire body emits a cold abstinence aura. The girls only have the guts to look from afar and not get close.
Later, it was rumored throughout the entire school that even the study god would fight and hit on girls. Whoever dared to provoke his girl, he would teach you how to be a person at every minute. The night of the graduation ceremony someone saw him blocking Gu Siyi in the corner. He didn’t stop kissing even when she cried. He bit her lips and said in a raspy voice, “I’m going crazy…”
During college finals, Gu Siyi almost bursted out crying, “I’m such a failure. I won’t be able to find a good job in the future…And if I can’t find a good job, I can’t provide for myself…”
Xia Zhijun played with her pink earlobe and remarked, “I’ll take care of you.”
After they graduated, Xia Zhijun created a research company and Gu Siyi became the boss’s wife.
The commercial rocket, “Star of Siyi” was successfully launched. So everyone knew that the new technology superstar, Xia Zhijun has a wife who he spoils a lot.

- Description from Novelupdates