Both my parents were commoners .

It seems they were childhood friends who attended the academy together, then were both chosen as members of the Hero party…… Well, I was born after they got married and .

In a word, this elegant mansion was built after their marriage .

And, there is a s.p.a.cious exhibition hall in which a lot of weapons and magical tools both ancient and modern are usually locked .

Inside, there are swords and armor that are placed in a showcase or displayed on the walls .

It is probably as a hobby that my father, a magic swordsman, acquired numerous weapons after marriage .

He claims to have mastered a hundred martial arts, but I’ve never seen my father use a Halberd .

However, there in the back of the armory like exhibition hall, there is a foreboding thick door .

It is a s.p.a.ce that can only be opened once a year, wherein lies the treasure which changed the history of the world and saved the human race .

“Now then, Little Man . While I retrieve a rag, do go inside and reclaim your childhood . If you want to steal it, please do your best . Well, it’s impossible for a half pint to pull out the sword that’s sealed on the pedestal . ”

“I’m not stealing it! It’s… Well…… I wonder what it will be like to see it now… . ”

Sadiz tells me with a smile . I felt awkward, but I unlock the door with the key I received .

The room within spreads out to a perfect square floor .

On the floor a five-pointed star magic circle drawn, and in the center is a sword stuck in a pedestal .

“…… The Sword of the Hero…… The strongest in the world… Hmm?”

A room that is only released once a year . I wasn’t here last year or the year before, so I’ve come into this room for the first time in a few years and looked at the sword…

“…… Huh?”

Instead of the sword, I was looking at something else .

『Hmm… the door opened… I see, a year has pa.s.sed… how many now… about 15 times…』

It’s not my own words . There should be no one within the seal because it is usually locked and no one can enter .

But before I entered, there was already someone there .

『…… Hmmm!?? This one… Oh…… Hiro’s progeny… was but a toddler, but now a little grown-up and resembles Hiro . 』[S1] 

“No, who are you!! Why are you here?”

『…… What?』

Wait, why are you surprised?

Moreover, he’s not human!

Long, fiery hair as if dyed with blood . Sharp and majestic devil horns that extend from the head .

The medieval beauty form that would be acknowledged by both man and woman is engraved with a suspicious pattern around the eyes .

A mysterious demon dressed in a purple robe that covers the whole body .

I raised my voice and prepared myself .

『…… Huh…… Truly… child…』

“Heh!?”

『Can you hear my voice? Do you recognize my presence?』

“W-What the h.e.l.l are you saying! Wait, how did you get into this room? Are you a demon? A robber!?”

『What!? What do you mean… Surely… . . Has nothing happened in my fifteen years of isolation?』

Fifteen years? What’s this guy talking about? No matter how you think about it, he doesn’t seem to be tangible, and yet you feel a strange presence .

This isn’t normal!

“Little man… you’re noisy . Did you actually try to pull out your sword?”

“Sadiz! Watch out, there’s a strange guy!”

“……?”

At that time, Sadiz heard the commotion and came in holding some cleaning equipment .

This is not a problem .

Although Sadiz is a maid, she has graduated from the Academy with excellent grades and is qualified as a 【Superior Warrior】 .

I don’t know why such a person is content with being my exclusive maid, but when I was a kid, she was as talented as my personal escort .

With both Sadiz and I, no matter who this guy is…

“Little man, there’s no one there…”

“Eh?”

“…… Did messing with your virginity end up causing hallucinations and delusions? Oh dear…”

I was surely able to see the demon within the seals, but Sadiz was amazed by the fact that nothing was visible .

“Eh? What, why? You’re there, aren’t you?”

“Lil’ Earth, please give up on this strategy . Trying to scare me and pushing me down to get intimate is meaningless . So stay a virgin for a while . ”

“No, no, it’s not that!!”

“Well, now I’m ready . Don’t make too much noise . ”

She really can’t see it? Sadiz has gone in preparation for cleaning again .

『…… Apparently…… the only one that can see me… child… is you …』

“Wha…!?”

『Even so…… When I had a body, I had lived for tens of thousands of years, but… it brings me some joy to have a conversation with someone for the first time in a dozen years… I’m weakened… under the circ.u.mstances I would lose to humans… . 』

You’re stupid, aren’t you? No way, I’m the only one who sees you?

『Confined to this s.p.a.ce… The only intrusion is during the yearly cleaning… for such an occurrence, what does it mean? Mischief from G.o.d? Well, either way… It’s all about you… my instinct tells me . Even though I was obsessed with this sword, but… Child, you are curious as well!』

“What, what…”

『Tis ironic, but… In a sense, a stroke of good luck . I couldn’t see anything outside because this sword hadn’t been taken out since I was overthrown . Huhahahahaha!』

“Uh, W-What is this? Hey, what the h.e.l.l is with you!”

Then, the demon approached me, trembling with a smile mixed with ecstasy and madness .

“Stay away! No matter who you are… I know you’re listening! You wanna get beat up!”

I picked up the mop that Sadiz had put in preparation for cleaning .

I held it like a sword, further increasing its power by imbuing lightning magic that I excel in .

『Hoo… 【Magic sword】… But…… Tis unrefined . Mediocre . A far cry from Hiro’s prowess . 』

“Heh!? Y-You…!”

I was so engrossed that I swung at the demon . However, the demon who I thought got hit without doubt slipped through my attack .

『Tis no use . Your attack is meaningless to a spiritual body . However, tis you who is fortunate as all that remains is a spiritual body . 』

“What the…!?”

『With this level of magic sword, even if you train for a hundred years, you would not even be considered an enemy during the era I was active . 』

“…… wha . …”

『No matter, you’ll be in my care from now on . I shall give you my name . 』

I threw up as the demons looked into my eyes .

『I am “The Great Demon King Tre’ainar”[S2] …… who once sought to conquer the world, but was slain by your father and his companions . 』

“Huh!?”

『The modern world that was lost to me… I shall see it through you, child . 』

And then, I lost consciousness .

 [S1]Enter the Great Demon King! I decided to have him use a more sophisticated speech pattern . Light Shakespearean speak (like using “tis” instead of it’s) and more high born vocabulary . So yeah, to the THESAURUS!!!

 [S2]Ooooh $%#@! Here we go again! The Great Demon King, the t.i.tular “Master” is literally named “Trainer” . So I played around with the name to make it look more foreign!