I, The Dragon Overlord - Chapter 598 - High Energy Detected!

Venshiro, a young ronin bound to the Black Vein Blade, is hunted by clans who would kill for the curse he carries. Every time he draws the sword, it takes something from him—his memories, his soul. But the blade remembers everything.And now, it wants more.

Fate is a funny thing.

In the past life, he was an aerodynamic engineer of a well-known company, and in this life, he is a college student of a famous school.

When the two identities are perfectly integrated, what sparks will appear.

His life experience is also slowly uncovering the mystery, whether he can beat the tycoons of this era, and whether he can stand at the peak of world business.

- Description from novelbuddy

Once upon a time, a hero had been summoned to a different world in order to defeat the demon king. After the war stretching 3 years ended the commendable hero slew the demon king. And he was forcibly deported back to earth after being dismissed.

Such bullshit!

Elves in addition to beast race, dwarfs and demon race. Even though I wanted to make a harem in the different world I saved! My dream will not come true on earth, where there is no magic at all. Thus, the hero returns on his own. Without the blunder of being extradited to earth this time, he will build a harem of his own in a different world.