In this world, many kinds of monsters run rampant, feasting upon countless human beings.
And among these monsters, the apex predators are known as demons, creatures that can only be harmed by silver, Holy Magic, and sunlight that would reduce them to dust.
Most monsters saw human beings as food, causing deaths to countless innocents.
In order to combat these monsters and demons, the Order of Protectors was founded centuries ago.
Many bases exist in different locations, each controlling their own branch of Protectors. The protectors are divided up into five ranks, based on ability.
The highest ranked ones among the Order of Protectors are known as the Guardians.
Guardians are known far and wide as the supreme swordsmen in the land. There are not many alive who can match their skill.
In the Southern Plains, the declining branch of Protectors, headed by a former member of the Guardians, Elder Hiromasa Dashi, was experiencing a rather sharp decline to the point that the elder planned on shutting it down.
Hiromasa always wore a white mask with red stripes, with only his sharp, eagle-like eyes visible.
Their branch was called the Blue Sparrow Branch.
Once this branch had many members in it, but with the increase in monster attacks, the casualties skyrocketed. Maimed, fearful for their lives, and seeing their comrades perish one after another, many chose to quit. By now, aside from the elder, there was only one active member left.
That young man's name was Nagare Shirosaki (16), and the elder considered him akin to a grandson.
Hiromasa (74) never had any children and had no living relatives. So Nagare was pretty much the closest thing to a family Hiromasa had.
After Nagare's family was slaughtered and eaten at the hands of demons, Hiromasa practically adopted the boy and taught him the skills needed to take his revenge upon those monsters.
At the time, the decline of the Blue Sparrow Branch had already begun, and there were only about ten or so members left, and as years went by, the more graves there were.
Now, only Nagare remained.
'I am too old to continue this. I will write a letter of recommendation for Nagare to transfer to another branch; he will find more opportunity to hunt demons there rather than rot in this place'
The truth was that Nagare had a lot of room for growth as a swordsman, and Hiromasa hoped that he would gain better training and more practical experience with the swordsmen in the other active branches of Order of Protectors.
Hiromasa wanted Nagare to transfer to a branch known as the Golden Dragon, known for their skilled swordsmen. There, Nagare would meet the current Guardians, and with their guidance, he might reach their level one day.
'Still, the lad is as stubborn as a mule. How am I going to convince him to go there and leave this branch to die out completely? I wonder…'
Then, Hiromasa heard a noise as Nagare entered the building, but this time he was not alone.
He was dragging a person who was tied up with a rope.
"Ouch! My butt! My butt hurts! Slow down buddy!" the man in tattered kimono screamed to no avail.
"Nagare, who is this?"
"Gramps, I caught this monster, but I can't kill it. Just look!"
Nagare proceeded to behead the tied up man with his sword in a single slice.
Nagare clearly just killed him,
But then, something strange started to happen.
Within less than a minute, the entire head grew back on the man's body.
"I tried to kill him every way I could think of, but silver and sunlight have no effect on him, gramps, how do I kill this demon?"
"The question is, Nagare, whether this creature is a demon or not. Strongest demons can be somewhat resistant to sunlight but not immune, as for immunity to silver, I have never heard of that"
Most monsters were weak to silver due to its purifying properties. In a sense, silver was a natural poison to them.
"But there is a way to be completely certain. Holy Magic."
Taking out a small bottle he kept on his belt, Hiromasa splashed the contents upon the tied up man's face.
Instead of burning him, there was absolutely no reaction.
"I don't know what he is, but this guy is not a demon or a monster for that matter"
"Told you" the prisoner muttered in annoyance.
"But then, how can he regenerate his injuries if he is not a demon?" Nagare asked.
"Dunno, I have just always been this way"
"Shut up! I did not ask you!"
Nagare stuffed a cotton ball into the man's mouth, making him stop talking.
"Nagare, there is a possibility that he is merely a human who had awakened a talent, which happens to be regeneration"
"Could that really be the case?"
"No demon or monster can survive Holy Water, so that rules out that possibility. So a human being who possesses a talent is the best explanation I can think of"
"I don't understand" Nagare shook his head.
"Then…How about we ask him?"
Hiromasa now removed the cotton ball from the man's mouth.
"Young man, what is your name?"
"Shoyo, Shoyo Ryoma" he muttered.
"Shoyo, huh? I see…Then how about this, we will think of what we are going to do with you tomorrow, until then you will be here"
"That sounds fine by me" Nagare nodded.
"Ok, but why am I still tied up?"
"Can you truly blame us? While it is probable that you are simply a human, we cannot be completely sure, so until we know what to do with you, you will be kept restrained, for our safety"
"Well, that sucks, oh well, I don't mind" Shoyo closed his eyes and drifted off to sleep.
"Gramps, have you really never seen someone like him?"
"Well, as far as regeneration goes, it is a common power for monsters to have, but it is my first time seeing a human being who possesses it."
"Provided that he is a human"
"If nothing happens by tomorrow, then he can be let free"
"But what if he tries to kill us?"
"Then we will have to seal him away. That is the only way I can think of to deal with an immortal"
* * *
"Good Morning! Do you wanna have some tea, perhaps?"
"Yeah, thanks…Wait what!"
Nagare realized that Shoyo was no longer tied up and was serving him tea.
"How did you escape?"
"Well, you guys were generous enough to leave my mouth open, so after a couple of hours of chewing on the ropes, I managed to break free. Very cool, right?"
"Not cool! Not cool at all!"
Then, Nagare looked down and found that he was only wearing his underwear.
"You…"
"The name is Shoyo"
"Shoyo, why am I almost buck naked? And…Why are you wearing my clothes?!" On one side, Nagare was now sure that Shoyo was just a human, as the elder stated; he was still alive, so that ruled out the possibility that Shoyo was a man eating demon.
But on the other hand…Shoyo was not exactly a normal person. Nagare felt a little violated after Shoyo stole the clothing he was wearing while sleeping.
"Well, yesterday you cut up all the clothing I had, so I thought it would be fair for me to take some of yours. Oh, by the way, before you say anything, I am not into guys"
"I have spare clothing, you know? Did you have to take the ones I was wearing?"
"Now that I think about, that may have been a better idea, oh well; I was always a bit of a klepto…"
Irritated beyond compare, Nagare put on his spare kimono and proceeded to head out.
"Where are you going?"
"To patrol, I need to make sure that the villagers remain safe from monsters"
"It is not like the monster attacks are frequent, right?"
"They happen nearly every day, often several times"
"Oh, ok, I am coming with!"
"No way! You are staying here!"
"Naga-kun, it is not like you can do anything to stop me, right? Cut me up all you want, I will just keep walking without problem. Also, it will take time, the precious time you could be focusing on protecting the villagers…"
"Fine, do whatever you want, just don't get in my way"
"Splendid"
Just like that, the duo of a Demon Hunter and an immortal teamed up for the very first time.