This Eroge Won't Make Me Fall! - Chapter 63 57.3: Maria [R-18]

The world is big, but I am the only one who is orthodox.Sweeping the world's immortal sects with the power of the Celestial Dynasty.A strong man who practiced the 'Way of the Emperor' came to a world full of immortal sects, and a secular dynasty that was despised by the practitioners gradually came to be on an equal footing with all the top immortal sects.The law of the dynasty is that everything in the world is the king's land, and the shores of the land are the king's ministers! There is only one orthodoxy in the world, and all immortal sects are illegal organizations!

Vid: My time at Hogwarts is only seven years, and excluding holidays, that's only 266 weeks! Even if I could thoroughly read one book a week, 266 weeks is only 266 books! How many Magic Books are there in the Hogwarts library? Thousands upon thousands!Time waits for no one, so how can I not seize the time to study?! I will not allow anyone to disrupt my study environment—not even the Dark Lord!

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.

A strange store which sells everything suddenly appears in the town. The Owner of the store is a young man and anyone who tried to mess with him %$#@.

The products of the store are expensive, yet the queue outside the store never stops.

“So what, If you're an emperor. I'll fight to the death with you if you try to break the queue.”