I Opened a Café in Another World. - Volume 2, Chapter 10: I hear my stepfather’s opinions.

Criminal Psychologist, Su Xiao Pei, who was an leftover woman in her modern life, was informed by the God Of Marriage, Yue Lao, that her destined lover was in a car accident, his soul was sent to another world. Su Xiao Pei was ordered to bring back this strange man who was connected to her by the red string of fate. Otherwise, she will live the rest of her life in loneliness, with no one to support her.
But how does that man look? No idea.
What’s his personality like? No idea.
What does he do for a living? No idea.
Can she not go? Of course not.
Su Xiaopei, who believes in all things logical has run up against a serious wall this time.
The bottom line: This is a story about a modern female psychologist who has traveled back in time and an adorable warrior as they talk about love and solve crimes.

- Description from Novelupdates

Shuu is a member of the literary club that can’t write. One day, he gets a mysterious message on his phone from a girl called Eina, and from that impulsive contact, they begin to exchange messages. They talk of things like their shared interest in novels and grow close. However, when they try and meet, they discover a shocking truth. Eina lives… not in the present, but five years in the past! How will their love develop, parted by five years of nights…!?

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.

Yiwen traveled through time, but Yiwen didn’t panic at all…

Because he traveled with him, as well as the character template in the mobile game, and the five devil fruits obtained by the lottery.

Yiwen believes that she can rely on the special physique obtained by charging six yuan for the first time, and the devil fruit in the backpack, and become a strong party in the world of One Piece.

Until Yiwen opened her eyes and saw a crimson dragon.

Only then did Yiwen realize that this was not One Piece at all, but Fairy Tail!

Start to capture Erza? The start was captured by Irene!

- Description from novelbuddy