Black Clover: The Son of Fire Dragon Igneel - Chapter 327: SFDI -

Going for a swim, she ends up in an ancient wild Beast World and ends up being brought home by a handsome wolf.
She wants to stick to the handsome wolf, stock some salt, farm some land, look at some handsome men and grow old like that, but the handsome wolf pounces on her every day.
What? He wants her to have babies?
NO~ NO~ NO~ There is no happy ending to interspecies marriages, hurry and let go of me handsome wolf~

- Description from Novelupdates

Julian Weber is an officer in the U.S. Army Corps of Engineers and a graduate of Westpoint Military Academy with a degree in civil engineering. As U.S. involvement in Afghanistan comes to an end, Lt. Julian Weber finds himself involved in a terrorist attack by the Taliban, which claims his life.

However, he quickly finds out that death is not always final as he is reincarnated into the body of a Baron’s son and heir in an alternate Earth set in Late-Medieval Europe. In an era of political turmoil and civil strife, the Baron’s young son is named Regent of the Barony of Kufstein and forced to contend with feudal powers. Will he be able to institute reforms leading his Barony into the age of industry?

Or will he succumb to the pressure of his feudal overlords and a corrupt church that seek dominion overall?

One day, Luo Jian woke up from his sleep and found himself in a locked chamber where the door and window were all sealed. A note with a few lines written on it was tacked to the wall: “Escape from this room within an hour, otherwise, you will die.”

There is a sequel called Reincarnation Night (轮回之夜) that takes place in the same universe but has different main characters

- Description from Novelupdates