MTL - The Manga of Ten Thousand Realms - Chapter 350

A con-man and policewoman that are legends of their respective professions suddenly die, then are reincarnated and return to the Tang Dynasty of ancient China as little kids.

Accepting their second chance and forced restart, they choose to use the modern knowledge and specific talents that they have in their previous lives in order to live comfortably in this new life.

- Description from Novelupdates

Houjou Yuuji, 30 years old, jobless, hikkomori for 10 years. Using his parents’ death as the impetus, he decides to rid himself of his hikkomori life and leaves the house. What awaited him, however, was a different world that he was not used to, creatures strutting about that he didn’t recognize.

This is the story of a man transported to the another world, as he lives in relative peace with his beloved dog Kotarou – his house, with electricity, water, gas, and the internet somehow still connected.

One day while exploring the forest near his house he finds a girl named Alice, and becomes her guardian. Thus, 4 years after he is transported to this world, Yuuji resolves to venture into his first town.

Yang Feng somehow transmigrated into a different world and received a legacy of an ‘ancient high tech’ family, which does not directly raise his power, but gives him the technology to build things which are way more advanced than the seemingly medieval world.

But to build something you need resources and energy. To receive resources you need strength. To gain strength you need knowledge. To gain knowledge you… need strength? or a background? Or maybe a fully armed army of high tech robots who aren’t afraid of death?

But is this legacy really for him to keep?

- Description from Novelupdates