Why did it have to be like this?!

I was a programmer at a black company, but I got hit by a truck and transmigrated to another world.

At that moment, a sage's soul, to my dismay, took up residence in my head.

The sage's soul had something left undone. That was...

"To defeat the Demon King."

The ordinary me, under the incredibly rigorous guidance of the sage's soul, spent 30 years growing strong enough to be called a hero.

And then, I challenged the Demon King and defeated him!!

"With this, the sage's soul will finally find peace."

I was convinced that my slow life in the other world, complete with a harem, would finally come true.

But to my astonishment.

The moment I opened the Demon King's treasure chest, I was sent back to Reiwa Japan.

What's more, it was one minute before I was hit by the truck.

I couldn't bring back any magic or items.

However, the skills I had developed by defeating the Demon King were still intact.

In Reiwa Japan, the 'Demon King Buster' who returned from another world showcases his unrivaled abilities in the business world.

And he hasn't given up on his harem either.

His dream is big: to establish the world's number one company!