Onee-chan Will Become a Hero and Save the World!

I, a normal high school student, was abruptly summoned as a hero candidate one day, along with my younger sister, and my four year younger little brother. Unfamiliar with the world, and mutually taken hostage, we had no option but to comply with our summoners.

In the unfamiliar life we were forcibly abducted to, we were given no time to grieve, only time to learn. The country’s common sense, morality, living environment, way of thinking, eating habits. While all of this was being hammered into us, we each awakened an extraordinary ability. My younger sister received the holy barrier, my younger brother the holy power to purify demonsー and I gained speed beyond the limits of a human.

My sister was embarrassed, my brother was delighted, and I was terrified.

If these powers didn’t develop, we wouldn’t need to fight as heroes. To risk our lives to defeat demons. What if they’re hurt? What if they die?

One gloomy day, as I repetitively trained the use of my ability, I overheard a conversation between the King and pope, their plan for the most suitable one to be sent to take down the demon king, and for the others to be kept as substitutes for emergencies.

ーI’m the older sister, so it’s my duty to protect them.

Because I don’t care what happens to me, only to those children.

With that in mind, I seriously focused on the tiring training, making more effort than my brother and sister. For me to become a hero, and defeat the demon king. I sparred until I coughed up blood, swung my sword until my skin peeled offー indisputably proved my skill, and was finally chosen as the savior by the King.

But surely, if I fall, they will use those two as hero candidates.

So I will not fall.

“Why is it you?” my brother asked, staring angrily with grudge filled eyes.
“Why are you doing this?” my sister questioned, crying and muttering that she wants to go home.

My skill and strength are only average, so with only the power of speed, I am challenging the demon king nobody in this world could defeat. But, no matter how hard it is, no matter how frightening it is to me, a normal high school girl, if I fail, those two will end up facing the demon lord, and in the worst case, be killed.

It is certain they will be used, because their powers are too suited for fighting the demons.

While hiding my trembling fingers, “Sorry,” I apologized and smiled at them.
The people who will protect these children in this world, is only me.


While my brother and sister lowered their heads to the nobles who treated them warmly and would be taking care of them, I continued cutting down demons with my sword.
As soon as possible, for the sake of returning my siblings to our original world, I ignored the pain and scars. Though I was always tormented by loneliness, just returning to the capital and seeing my brother and sister for a short time was enough to bring me courage.  Stained by blood, and scarred everywhere; looking at my figure which was so disfigured recovery magic couldn’t fix it, my brother stopped saying he wants to be a hero. My sister just silently handed me medicated cloths.

After two years of living like this, I finally defeated the demon king.

Everything was over. When I returned to the capital I was enveloped by the triumphant celebration, and everyone praised me. The masses, the nobles, the Pope, and in the end, even the King.

While apologizing to those who wanted to hear how the demon king fell, I headed to the aristocratic house where my brother and sister were staying. I thanked the aristocrat who was surprised by the sudden visit, and was guided to a room after I asked to see my sister.

In the long absence, my brother has grown taller, and my sister’s hair has grown long and beautiful. While concealing my missing parts, and hiding my tragic scars behind my helmet, I stood in front of my brother and sister, and spoke in a voice hard to hear because of my mangled throat.
“Everything is over.”
My sister hugged me while crying, repeatedly saying “I’m sorry”.
My younger brother showed a pained expression, and turned away without saying anything.
I was just glad that the two of them were safe.

I told them with my broken voice, that with this, we can return. We can go back to our peaceful lives, free of conflict.

ーAnd yet.
Even some time after I returned, the subject of our returning home didn’t come up at all.
Though the celebration and ceremonies of victory were all past, though everything was over, there was no word from the King or pope.

As I muttered to myself, “What’s wrong…”, my sister made a troubled smile, and my brother put on a serious face, as though he was thinking deeply.
On one of these troubled days, the pope called me to the blacksmith requesting my cooperation in creating a holy sword.

“I want to create a holy sword so that the country is safe even after the hero is gone.”
At the pope saying this with a smile, at last I hit the limit of my patience that’s been building up every day.

“I don’t care about something like that. Now that the demon lord is destroyed, it will be safe for hundreds of years. If it’s just normal demons, the knights can easily take care of them. I just want my siblings to return to our original world as soon as possible.”

With a serious expression, the pope pointed towards the blast furnace.
When I looked at it, something like molten iron was wriggling inside.

He spoke.

“The holy presence and great power of heroes, they should be passed on to future generations. The lineage of the hero is full of energy. However, not all of their progeny are guaranteed to inherit their talent, so if they are allowed to live indiscriminately you might end up with useless progeny with authority. Instead, it’s enough to let one or two of them live. In addition, it’s impossible to return a hero to their original world in the first place, so it would be troublesome if you stayed alive.”

So, they’ll put my soul in the holy sword.

So a ‘hero’ can’t return to their original world?
Then, I wonder if those kids can return.
No, first of all, leaving descendants in this world?
How many people would be willing to return if they had descendants?
No, it doesn’t matter if they can’t return in the first place.

What are lies, what are threats, my thoughts go in circles without any conclusion. Even in my confused state, I can understand one thing. These people, have no intention to return those kids home.

As I try to grab the Pope in rage, a silver barrier I’ve seen somewhere before blocks me.
…..Ah, that’s right.
I haven’t seen this color in a long time.
The golden holy power of my brother, and the silver barrier of my sisterー

The pope laughs as I stiffen in surprise. “Your younger sister has already agreed.”
A soldier opens the door.
My younger sister slowly enters, her beautiful face pale, and stands next to the Pope.
Her eyes were dark, and she showed a troubled smile. “I want to live. Sorry, big sis.”

She wasn’t someone who would show such a face.
What did you do to this girl while I was fighting the demons一 is what I want to ask, but my collapsed vocal chords release only a groan.

My sister’s barrier holds my stunned body close to the furnace.
It isn’t like I’m not strong enough to break free, but if I do, the backlash will go to my sister. If I break this barrier, my sister will be severely injuredー as I hesitate, before I know it, I’m falling over.

My sister saying “goodbye” with a smile even as she cries, my stomach pierced through with a spearー this was my last memory as a human being.

From there, my consciousness was hazy.
I… wanted to go home, I didn’t want to fight.
Being summoned by force, being betrayed by my sister, I had no grudge; I only felt sad.
Despite obtaining special abilities and being called a hero, I was still just a cowardly child, and so even though I was betrayed by the one I was trying to protect, I did not have the courage or willpower to resent them.
Though I had some enmity towards the pope, that too was overwritten by sadness.

A variety of emotions are jumbled together inside me, but little by little, they condensed into sorrow. However, even as all these emotions became one, another person, another person, another person, another person was added along with my body among the molten iron. I don’t know how many sacrifices were dedicated, but the innocent people were probably convinced in the same way as me.
An endless stream of heartbreaking emotions; shouts of hatred, lamentation, overwriting “me” and my sorrowー

In the end, the holy sword was not completed.

Formed with a hero as the origin, a sword of resentment.
A sword with too much power forced into it, a sword whose balance was destroyed by excessive sacrifice.
A sword that absorbed too many grudges to become a holy swordー it was my younger brother who first used it.

My brother took the cursed sword in his hands, and charged into the king’s castle. Though as a hero candidate he mastered his ability thoroughly, he was still just a boy who lacked any mastery of swordsmanship or physical combat. An ordinary boy, who feared combat after seeing his sister’s scars.

However, as my memories and abilities flowed into him from the handle of the sword, my brother moved quickly. Faster and faster, faster than anyone else.
Just like me, when I had life.

My younger brother struck down my sister who was trying to put up a barrier to shield the castle, and then continued fighting against the multitude of soldiers who surrounded him, until his body destroyed itself with the speed forced upon it by the cursed sword. Surrounded by soldiers, being skewered upon their spears, he hugged the sword close and refused to let go.

Tears of golden magic fell upon the blade held in his embrace.
He stopped breathing after squeezing out his last few hoarse words.

“Sorry, big sis.”

The tears of my brother’s sorrow, the golden magic of purification pouring out with his life, his blood dyeing the white blade red, it awakened “me” who had lost all sense of self after being buried in the karma of others.
And soー the very first thing I understood after waking was that my beloved brother and sister had killed one another, that both of them were dead.
In my vague consciousness that was barely awake, in this cursed sword, a new grudge against the world was born.


A long time after the death of my brother, the next one to hold me was a young man. A chosen youth, the hero of the country. Though his ability was lacking, like me in the past, he obstinately fought the demons anyways.
Therefore, he was used.

He was manipulated at the convenience of others, failing to notice the trap stretched around him, until finally he was falsely accused of treason. Chased by those he should be protecting, forced to cut others down to live, only increasing his notoriety as a murderer. Yet, he still continued to believe, running from east to west, insisting his innocence to his colleagues.
He was a strong man.

Though he was weaker than my past self by several levels, the strength of his conviction was undeniably that of a hero. After him, I passed through countless hands, but he was the only one who wielded me for a long time and did not collapse in mind or body.

The cause of his death was poisoning, by his parents. He held the sword as he suffered from the poison, cutting down his parents as they cursed at him, and died.
His grudge, to the cursed sword, was rather thinly colored.

ーFrom there, by another person, and another person, I was brought along in the processes of betrayal and revenge, as they died while spitting out grudge filled words.

Little by little, their grudges slowly dyed me black.
I was a symbol of my grudge, a symbol of the grudges of all those who once held me and no longer had breath; to the “country of heroes”, a curse.

As I died in sadness, I had no desire to do something like curse someone or become a cursed sword inscribed with grudges. Rather, I only wanted to hold onto the sorrow of betrayal, and the sorrow that they could not return. But, my brother’s tears that rescued “me” were too weak to cut the chain of grudges dwelling within the cursed sword.

Though the royal family, fearing the curse, sealed me in the church, the curse overflowing from the inside of the church still swept over the “country of heroes”.

And, destroyed it.


Unnoticed, the power of resentment gradually pooled together, and at last I became able to produce a spiritual body imitating a human. Though it had my former shape, before my body was disfigured to the point of being unrecognizable, everywhere, everything was dyed black.

As the years passed, even that bit of self which my brother saved began to be stained black. Regardless of my intention, the mere existence of a cursed sword spreads its curse indiscriminately. But, as long as I was sealed, as long as nobody wielded me, this cursed sword shouldn’t have been a threat to anything other than the “country of heroes”.
As long as I was sealed, it should have been enough.

“If you hold me you’ll be swallowed up. So throw me away, or break.”
I kept whispering.

After I gained the ability to speak to my holder, I advised this, again and again. But, no matter how hard I tried, nobody listened.
Because, I’m a cursed sword. Granting people great power, and dragging them down. No one who held me cared.
So, I was passed on.

Even though none listen, again, today, I whisper in the ear of a new victim.
Even though I know it’s useless, I can only do this.
Because I can only remember “myself” by doing so.

Already, not much time is left.


The cursed sword that failed to become a holy sword; traveling between the hands of foolish heroes who reach for it, though they know they cannot bear its strength. Spreading its curse, and traveling the world at the side of its victims.

Still, the cursed sword becomes stronger.
Spreading its curse, leading those who hold it to ruin, while dreaming that someday, someone might destroy it.

Until the girl tied to that blade, cursed the whole world.