The Legendary Mechanic (WN) - Chapter 36: New Blueprints and New Terms

One day, Yoichi who grew up while not knowing his parents has received the news of his father’s death. His father left behind a testament——which said he is to pick only one out of five ‘little sister candidates’?!

"I want to run away from everything."

This is an alternate history. Decades after the fall of the Eastern Jin Dynasty, the world is still in chaos, although there is hope for reunification.

After spending half a year in the province, Cheng Yang took a luxurious cruise for seven days.
Accidentally hooked up with a CEO on the way.

Later, Cheng Yang found out that he was pregnant.
Just as Cheng Yang was preparing to secretly give birth to the baby, it was a coincidence that he fell asleep in the big president’s bed.

It’s impossible to run with the ball, his man is handsome and rich.
Must cling tightly and can’t be torn down.

- Description from Novelupdates