Tomodachi no Imouto ga Ore ni Dake Uzai - Volume 4, Prologue

After Reincarnating into Naruto World at the Warring State Era as an Uzumaki, Masahiko thought that he got a useless System. He lived for 48 years as a normal, below average Uzumaki Shinobi.

That changed when he finally knew how the system works the day of his 49th Birthday!

- Description from Novelupdates

The system: We must take the plot seriously!

Mo Fan: Ok.

The system: We cannot be OOC!

Mo Fan: Yes.

The system: We have to be cold. We must be ruthless. We cannot lose ourselves in this imaginary world.

Mo Fan: …no problem.

Not long after…

Mo Fan: System, can we talk? Hold my gong and take him away.

System: ……

- Description from Novelupdates

Dale Mitchell, your average guy in a below-average job. But, what happens to him is anything but average. After hitting someone in his truck, his world was turned upside down, inside out, and more than fifty shades of grey.

Now, he seems to be something called a World Keeper, and must create and manage his own world. Is this his afterlife, or something else entirely?

“Screw magic, I want to learn how to do cool flips and stuff.”

Magic is awesome, until you've studied it for centuries.

Doevm reincarnates into a human to experience the path of a fighter to its fullest and swears not to rely on magic.

There is only one problem, a goddess stands in his way.

She pits him against both the hero and the villain for all of eternity.

How will he escape this, with magic or his fists? Maybe both?