Talent System In The Naruto Universe - Chapter 18. Konoha’s White Fang, Sakumo Hatake

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 Special Investigations Unit is a covert organisation that no-one in the city knows about, dedicated to investigating bizarre occurrences beyond the comprehension of the living. The Chief Zhao Yunlan isn’t a simple guy either, being the inheritor of the Guardian Order, he has always been a righteous conformist, excelling between realms of the living and the dead. While investigating a school suicide case, Zhao is attracted to the calm and reserved Professor Shen Wei, but the Professor seems to be rather fickle towards him…

- Description from Novelupdates

Set on a giant, almost finished bridge between Sadogashima and Niigata. Abandoned by the government, the bridge, and the giant man-made floating island at the center, has become a city of criminals and societal drop-outs.

Set in the same world as Durarara, but 15-20 years later. There is almost no overlap between Etsusa Bridge and the other novels.

To save someone, a poor boy unexpectedly acquired Dragon Blood as a body fortifier and even slept with a beautiful female CEO. By a twist of fate, he became the bodyguard of this female CEO, thus beginning a journey of an incredible turnaround.Female CEO, “Come to my room tonight to discuss work.”Long Fei, “Are you trying to kill me? Discussing work every single day for a month, can't you give me a break?”