Steel, Guns, and the Industrial Party in Another World - Chapter 319:

In short: an old lover gave me a little piglet.

Qin Zhuopu, a workaholic, has been single for many years. As he reaches middle age, his family is desperate for a child.

Until one day…

“Mr. Qin, your son is already in primary school!”

“???” I have only had one boyfriend!

Seven years after the breakup, the old lover returned to the wealthy family with a little fat pig in his arms: “Zaizai is a big eater, I can’t feed him. Zaizai’s primary school homework is too difficult, I can’t do it. I’ll give you guardianship from now on! Will you let me go to your construction site to move bricks? Son, say ‘Mommy’!”

Mr. Qin: (No, I couldn’t give birth to such a fat kid!)

Later…

Onlookers: I heard that Mr. Qin has adopted an illegitimate child born to his old lover by some woman?

Mr. Qin: Let me introduce to you, this is my own cub!

- Description from Novelupdates

Young genius Ren Zhong, suffering from a terminal illness, chooses the human cryonics project. Upon awakening, he finds himself in a desolate wilderness, beneath a gigantic blue sun and a duo of silver-white moons. On this unfamiliar planet, relying on the resurrection to rewind time and accumulate experience, Ren Zhong is determined to become a warrior. After experiencing betrayal, being wanted, and judged, he resolves to rebel against this unjust world and establish a new world order through war.Compress infinite time into a moment; anything can happen.Rising from insignificance, walking the seams of time, reversing billions of years of enslavement.This is the story of an immortal man and his comrades breaking the shackles of fate.

The Third World War has been ended by the efforts of Kamijou Touma. With that, he vanished. With the Magic Side regrouping, the Sabbath for their followers has arrived.

In the headquarters of the Science Side, Academy City’s strongest Level 5 Esper Accelerator has washed his hands off the “Darkness.” Along with Last Order and Misaka Worst, his days pass by peacefully with no sign of GROUP.

Hamazura Shiage has formed a new ITEM with Kinuhata, Takitsubo and Mugino. Peace has come to the hands of the alumni who have “graduated” from Academy’s Dark Side at last… at least until a new evil “first year student” appears before them.

— This is a follow up to the popular Toaru Majutsu no Index light novel series, where Kamachi-Sensei has promised to deliver new premises and give a totally new flavor to the fights and plot developments