After transmigration, Zhang Wu Ji is reincarnated into a youngster body with the same name.
Their differences?
Before reincarnated, he was a poor librarian that have to sleep in the library because he can't afford to rent a room. After reincarnated, he was a poor bastard that was despised by his two elder brothers because he was born with a worthless Martial Constitution.
But as a Transmigrator, he possessed a special System, [Upgrade] that allows him to strengthen anything in this world. How would he fare when he will need to earn, create, upgrade, and upgrade even more to reach the peak of the world?

Author Note:
This is a new attempt of mine for a serious piece of work. Grammarly already in used, but not the premium version one (it cost me a hundred pounds for a year subscription), I occasionally check my works and read the comments, so I hope more productive comment thanks.
English is not my main language, I am merely a graduate that came out to work, live, married, and write. I hope the mistakes that were done in the chapters can be accepted if it could, amended if I can, and advised if I get.

Thanks!

Very!

Much!