The Tender Beauty is Sweetly Doted in the 20th Century Novel! - Chapter 20: My Greatest Fortune Was Marrying You

A story of Gin, a young man who lost his memories before the age of 17 and became a magician. Living a quiet life running a cafe while researching magic, he is suddenly thrust into an unknown world. Moving between Earth and a realm filled with danger and secrets, Gin must rely on his knowledge, skills, and magical prowess to navigate the perils that arise. Ruthless and determined, he will stop at nothing to uncover the truth behind his lost memories and the mysteries of the world, using every tool at his disposal to rise above all

A class full of idols and beautiful people are sent to another world. However there is one guy who is ugly, fat and smells… our protagonist. This is his comedic story of evolution and the slow building of his harem. The first heroine is a gorilla.

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.

[Complete] Who could be more unlucky than her? She inexplicably fell down a mountain, lost her memory, was forcibly taken back to a villa by an overbearing and sly CEO for investigation, and on top of that, she had to deal with him constantly tearing at her clothes, wanting to find hidden cameras.The sly CEO said, “Want to leave? Complete your last task first!”“I want Italian ice cream!” a pregnant woman pouted with red lips, patting her swollen belly. “It's the middle of the night, darling, no ice cream, have a banana instead.” His gaze was burning. “It's not me who wants it, it's your son who does!” the pregnant woman cooed. Thus, a private jet flew directly to Europe overnight, and when she woke up in the morning, she and her baby were already in Italy.