My Civil Servant Life Reborn in the Strange World - Chapter 14.

“You need my help, Tesoro. You choose. A marriage with me or be torn apart by them” His voice was cool as though this wasn't a matter of life or death.I didn't want this life. My father had gambled a lot and left me with a lot of enemies and now I needed the help of Don Vincenzo LaRosa who was my high school bully and now the Don of the most powerful mafia family in Italy if I was going to survive it.It was just a marriage of convenience but I realized something. He wasn't helping me out of a good heart. I had been sold without my permission to him. I was the mafia's pawn.

He went from an ordinary student to a god-level master in manufacturing.
Continuously progressing, processing range from hundreds of meters to tens of atoms, processing precision from microns to nanometers to atoms and molecules, everything was possible.
Wassenaar Accord? The embargo against China? What we have banned are technologies that China doesn’t care much about. Most of the member states have to import technology from China, shouldn’t the member states have a meeting to discuss and bring in China as well?
Forbidden chip sales? Is there a mistake? We barely managed to maintain our low-end market with a large amount of subsidies, it’s already good enough that China didn’t initiate an anti-dumping investigation. President, are you sick?
Hmm, it seems like living cells can be processed precisely as well. Do you need to refine the cancer cells that you are spreading out?

- Description from Novelupdates

After getting forcefully reincarnated into a world of an otome game he has no clue about, the protagonist is then killed and brought back to life by the prideful villainess with one desire.

To rule the world.

As the ruthless girl’s Eternal Servant, how will he dodge the fate that the game system has in store for him?

Kawaki, who was born in the dragon vein of a planet (Altana), first met Umibozu who was traveling in the universe, and his girlfriend, Kouka.Later, he came to Earth by accident and met the teacher who affected his life —Yoshida Shouyou.He also met a group of friends. The most conspicuous among the group of friends is a fool with silver hair and naturally curly hair, a short man with purple hair, and a little devil whose catchphrase is “Not Zura, it's Katsura!”Gintama Doujin, not transmigration.