Naze Boku no Sekai wo Dare mo Oboeteinainoka? - Volume 1 Chapter 4

I made a deal with the Devil.Free of Charge.

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.

Polygamy is abolished.

We don’t have to force ourselves to live together anymore…

Six years ago, she signed the ten-month agreement with all her sorrows, and as agreed, she received the down payment. But when the agreed time came, the buyer did not show up to claim the 'treasure'. What was going on?Six years later, her precious son surprisingly told her, “Mommy, people might wear the same clothes or drive the same car, but I met someone today who actually has the same face as me! Can you believe it?”“Don't talk nonsense, how could someone look exactly like you?”Her son, dissatisfied, pulled his friend out. “Don't you believe me? Just take a look!”Lin Xiangwan took a glance, then, thud, she fainted, collapsing onto the ground.Who on earth... is this...?