My College Teacher is My Children's Mom - Chapter 655: San Bao Came Back

Akira Kisaragi traverses into the Bleach world, unlocking a check-in system.He initially thought that by checking in daily, he could become stronger, soon become the Captain-Commander, join Division Zero, punch Yhwach, kick the Soul King, and marry Unohana...However, the system's style wasn't quite what he had imagined.〈 Check-in complete, obtained Genryūsai Yamamoto's secret roasted sweet potato! 〉〈 Check-in complete, obtained exclusive attribute: King of Normal Attacks, effect... 〉〈 Check-in complete, obtained Retsu Unohana's... 〉Akira's eyes suddenly lit up!“Seems like this might not be so bad after all!”

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

The salaryman who had a dream of becoming a CEO has finally succeeded.

However…

There was no one. No one was around to celebrate his success. Then on his first day of work, news of the death of a former colleague that he had laid off came. Additionally, his family left him, who was only concerned about the company.

The life he thought was right crumbled right in front of him. Where the heck did it all go wrong? Then, another opportunity came for Han Yoo-hyun, who had plunged down into despair.

This time, for sure. He was going to live properly. He was going to change it all with his whole being. The new life that Han Yoo-hyun was creating.

That valued life that will outshine any other is unfolding now!

When he heard the immortal sister from heaven had died, Fang Ren didn't really care.When he heard he was going on a blind date, Fang Ren was a bit concerned.When he heard his wife-to-be was the deceased sister from heaven, Fang Ren cared a lot!