Prologue - The Crisis of Minerva

Our world is in a crisis, and we need help. For the last 700 years, thousands of humans have perished each day in unthinkable and gruesome ways, and despite our best efforts, we have yet to rid the world of... them… There are three things that keep this world running. Money, Steam, and "The Extraordinary".

If we lost any one of these three things, our world would immediately fall into anarchy. But one of these three things greatly outweighs the others in terms of value… "Item No. 3: The Extraordinary". Their role is to protect humanity and prevent as many deaths as possible.

But who are "The Extraordinary", and what are they protecting humanity from?

Very rarely, when a human is born, they may demonstrate strange abilities impossible to perform by regular humans. Things such as magic, ESP, combat mastery, and much more. It's unknown how these humans attained their abilities, but they have been dubbed "The Extraordinary Individuals".

It's estimated that every 1 in 1,000 humans is born an Extraordinary Individual, making the total estimate of extraordinary individuals to be near 7,400,000. These odds can be heightened if the parents of the child also possess extraordinary abilities.

But what are these "Extraordinary Individuals" protecting humanity from? Well, to put it bluntly, they're protecting humanity from total genocide… Living alongside humans is a mysterious race of demonic creatures dubbed "The Unusuals". They are terrifying beings of unsurmountable strength who must be stopped before Minerva is consumed by them. That's the name of this country...

Similar to The Extraordinary, The Unusuals also possess strange and mystical abilities. However, unlike the extraordinary, their abilities are heightened to the extremes, and their minds are corrupt with malice.

Their origins are unknown, as well as their motives. All we know about them is that they're out for blood...our blood… Every time an Unusual kills a human, they absorb their energy and gain their strength. This is cumulative...making some Unusuals frighteningly powerful depending on how many humans they have devoured.

Unusuals can also take the forms of those whom they have killed, disguising themselves as regular humans. This makes pinpointing their locations challenging as well. Documentations and Records of The Unusuals have been around for centuries, long before the establishment of the many training academies throughout Minerva.

The Extraordinary Individuals' jobs are to defeat these creatures and protect humanity, as they are the only ones who can do it. In order to properly defeat The Unusuals however, one must go through intense training at one of Minerva's many training academies. Eritoakademi: Institute for The Extraordinary, is the most elite of these schools, and regularly produces top-tier fighters each and every year.

Before the establishment of the training academies, Extraordinary Individuals would rely on their own self-taught skillsets to get by and protect their families. However, due to the rapid growth of The Unusual population, they became more difficult to manage. Their potency was simply too much to handle, and something would have to be done if humanity was going to prosper.

144 years ago, the first training academy was established by a man named Satoshi Ōtsuka. He called it "Eritoakademi", and it served as a place for Extraordinary Individuals to gather and train together, perfecting their skillsets before they set off into the real world to fight in the war against The Unusuals... it was a success, and the Extraordinary Individuals were now able to fend off against The Unusuals more efficiently.

However, in recent times, The Unusuals have grown much stronger, requiring more effort to defeat. There is a group of Unusuals who are concerningly powerful, much more than that of your average creature... they are an officially recognized group of intelligent monsters known as "The Mezurashi", and their abilities extend far beyond that of any Unusual ever recorded. There are currently 26 members of The Mezurashi, and they are classified by rank, going from strongest to weakest.

They are separated into two echelons, the Takai Mezu and the Hikui Mezu. The bottom 13, known as the Hikui Mezu, are constantly shifting due to them being slain by extraordinary individuals. But the top 13, the Takai Mezu, have only lost 6 members in the last 100 years...a true testament to their soul-crushing power.

It is rumored that if the leader of The Mezurashi, who is currently unknown, is slain, The Unusuals will fall, and the world will be saved... it has been the goal of every Extraordinary Individual to slay their leader, but nobody has ever encountered them. Eritoakademi is where those who wish to defeat them will go, in hopes that eventually, someone will rise to the task, and slay the ultimate demon...

In the many years since the establishment of Eritoakademi, thousands of students have come and gone, traditions were established, and the world entered the "Steam Age", where industry took over. However, even after 144 years of development, one thing hadn't changed...the academy... to this day, Extraordinary Individuals go there to train when they turn 16...

My name is Hachiro Karasagi, I'm 16 years old, and I am an Extraordinary Individual…