High-schooler Ryoma Mikoshiba finds himself summoned to another world by the warmongering O’ltormea Empire. Finding himself in a world that fits his talent and skills in martial arts to a bloody T, Ryoma sets down a path of domination and war.

The Oracle Princess Alfina suddenly announces an ominous prophecy, yet none heed her words. But a fateful encounter with the merchant Ricardo may see the disaster averted with the power of science, mathematics and economics from the modern world!

Ryoma Takebayashi never had a blessed life, but after his death, three great gods reincarnated him as a child in another world with swords and magic! Ryoma decides to live leisurely on his own, and his passion turns out to be researching slimes!

Ryoma, an ordinary high-schooler adept at martial arts, one day finds himself summoned to another world. Slaying his vile captors, he is on the run when he encounters two girls who will change both his fate and the fate of the continent.