In order to explain this, we first left the basement.
　We left the basement to see the actual "unknown substance" so that we could proceed more smoothly.

　The Oguni Foods Ya's is surrounded by mountains. In the large garden of the castle, which symbolizes this, my siblings and I stand side by side and listen to Mr. Di Prakula's explanation.

He said, "Yangtaki and Vortex Wave. I know it's going to be a long story, but please be patient and listen to me.

　And Mr. Diprakula, old and quiet, points to the dark sky, even though it's noon, with slow movements.
　I turn my attention to the sky above, thinking it's like a school lesson.

'First, let me explain about the 'unknown substance'. That dark cloud, to put it simply, is the 'source' of the power of the ...... world that failed to circulate.

　At the tip of his fingers is a dark, dark black cloud that can only be seen in CG in my world.

　Rather than a cloud, it's a fog.
　Rather than fog, it's darkness.
　My first impression was that "magical darkness" was covering the sky in the "magical world".

　Thanks to that, the abstract expression of 'source' that Diprakra-san mentioned can be swallowed just barely - but it seems impossible to swallow.
　To be honest, I wanted to raise my hand and ask a question. But I'm going to hold off until all the talk is over. Otherwise, I'm going to interrupt him a hundred times before he finishes talking.

"The 'source' is the source of all existence. "The source is the sky, the sea, and the earth. It includes the sky, the sea, the earth, the people who live there, the plants and animals - and even the intangibles, such as the planet's gravity and people's emotions.

　Next, Mr. Diprakra looked at the trees growing nearby and the ground under his feet, and finally pointed to his own head.

　At the same time, he poked the wooden staff in his hand into the ground with a thump and a hard thrust.
　Just as I felt like a wizard in a movie, the ground that was poked at me rose up and a small clay doll was completed by itself. It was exactly the kind of magic that exists beyond the screen.

Source' embodies everything in the world and gives 'life' and 'meaning of birth' to it. Even the stones and rocks, the forts and castles, have 'life' and 'birth meaning' in them. ...... Just because there is 'life' doesn't mean that one day you will die, though.

　And more earth wriggles and shapes a city of sand.

　There are about a hundred earthen dolls, about the size of a little finger, walking, living and sometimes - crumbling. The crumbled dolls return to the earth once and begin to live in the city again as new dolls.
　Gradually, however, the number of dolls born does not match the number of dolls that have been reduced and the number of dolls living in the city of sand dwindles.

　Perhaps he is trying to say that this is 'this other world' on a smaller scale.

Originally, the Source would sink into the depths of a star when its form collapses and take another form to be born on earth. ...... But that circulation is not working in our world today. The unformed source is lighter than air, so if left unchecked, it will accumulate in the sky. When a certain amount of it accumulates in the sky, it pours down to the earth like rain. That rain is harmful to beings with form. ...... something like this.

　Once again, Mr. Diprakra poked his staff into the ground.

　Then the soil on the ground lifted into the air and stagnated like a cloud over the city of sand. Next, he dropped the soil on the ground in a flurry, as if it had been poured through a powder sieve.

　Dirt piled up on the sand city.
　The puppets that lived there adhered to the soil on their bodies and gradually changed their physical form. It loses its human limbs, can't walk the streets, and becomes immobile as a distorted form of dirt dumpling.

'This pouring 'source' is called 'demonic poison' in this world. This "source" is called "evil poison" in this world, which takes a perfectly formed object and twists it into something else - a poison in itself. Isn't this a problem?

　So Mr. Di Prakula asks me questions and asks for my opinion.
　It may be out of consideration that we might get bored if we only talk about it, but now I'm so pale that I can't do anything about it.

　I've been imagining what those clay dumplings would look like in real life.

"...... Yeah, yeah. It's very troubling. Diprakra, can't that star's cycling action be reversed?
Hmm. If I can get the circulation back, the story will be over. Otherwise, you'll find yourself here. ...... That's right. Before I tell you about the mission of the Onushi, I'd like to tell you about an experiment we did before to restore the circulatory system. In other words, the story of your predecessor.

　There's plenty of time to talk, so they seem to be slowly going through the steps one by one.

　However, as a listener, I would like them to get to the point. Mr. Diprakra is polite and calm, but he seems to have a very roundabout way of doing things.

Before calling for your help, we the apostles looked for a vessel that could circulate the 'poison of evil' on an individual basis, a vessel that could be adapted to the 'poison of evil'. There was a precedent for this in ancient times. They imitated that past procedure and created three vessels that were able to adapt to the poison. It's a plan to train the three of them, and someday they will be able to circulate the demon poison on a star-by-star basis. By the way--

　Suddenly, Mr. Diprakra waved the tip of his staff to the side.

　Then the head of one of the dolls, which was safe, is snapped to the side with a swoosh. And then the soil that is the content of the doll comes out of the head into the air in a smooth manner. It is not only the minimum amount of the outside that can be shaped as a human being, but the doll became hollow.

"-- The 'vessel that can be adapted to the demon's poison' here refers to the person who forcibly extracted the 'source' of the 'self' and expanded the vessel of his or her body.

　I'm afraid to visualize it again in more detail: .......
　With a bit of nausea building up, I patiently continue to listen to the explanation.

...... Hmm. Now, what you're imagining and what we've done are not far apart. It's not so easy to get the circulation function and the space to receive the 'demon poison'. --Basically, he will die (・・・・・・). He loses a number of human functions and even sacrifices the most important thing about him. That's not all. Every time you use a power that deviates from that person, the world demands a 'price' for it.
-What?

　The next image was not something one could forgive.
　I stared at Mr. Diprakra, but he was not intimidated and went on to speak in greater detail.

'--and then that dead person will never die. They become the living dead and wander the world.
　Some have died and gained [the wind of freedom] and lost their freedom to live.
　It has been determined that they will never be able to return to their true selves.
　Some died and gained [unquenchable flame] and lost the bond with their loved ones.
　It was determined that they would never be able to tell their loved ones the truth.
　Some died and gained [unstoppable darkness] and lost their faith in someone else.
　It has been decreed that they will never be able to sincerely confront others.

　Mr. Diprakra told me matter-of-factly and glared back at me more forcefully than I did.

'I'm sorry, Kanami. We won't spare you. The 'compensation' is the most basic of all the principles of the world. You cannot create something out of nothing. The weak will have to go through their own trials before they can become strong.
'Maybe so: ....... But what we're talking about now is .......
I know what you mean. I see what you are saying, therefore, the one who put the "test" to the test was the one who chose to die a cruel death. I thought at the time that it was better than death. ......

　I swallow the complaint that pops into my head.
　I already understand the gist of the story.

　-- these people are trying to save the world.

　They're done cutting down the few to save it.
　They are telling us that without pretense and with integrity, before anything else.
　You can't blame them for not having an alternative.

　Besides, what's important to us now is not so much about the past as it is about the present.
　From now on, we may be the vessels that can adapt to this evil poison. I'm sorry for the people who have gone through this ordeal, but we need to learn more about their situation and make the most of it.

...... So, what happened to those three?
All three of them had successfully experimented with becoming vessels capable of adapting to the demon's poison, but they were incomplete. Even though they were able to empty their vessels and gain circulatory functions, their abilities were severely limited. Moreover, there were problems with his mind as well. Even though a flawed mind was a condition for being chosen, it was still really a terrible thing. ......

　Mr. Diprakra, who must have a strong will, dripped sweat from his forehead. It seems that there is a lot of pain hidden behind those sharp eyes.

'I don't intend to hide it. To be frank, I was in no condition to train. ...... I'm not here at the moment, but I promise to see you if you want me to.

　That the experiment was not meant to be. I could also see that he was deeply sorry for his actions.

　I could tell from his expression and the flow of his conversation that he had no intention of repeating the same thing to us.
　Although I'm in the position to receive an explanation, I regret that I didn't pay enough attention to Mr. Di Prakula, and instead of blaming him, I try to ask him a positive question.

'Okay, I get it. So, that ....... If the experiment had been completely successful, would the three of you have been able to properly become a 'vessel capable of adapting to the demonic poison' that could save the planet ......?
The direction of the game was not wrong. If he had grown up like that, he would have lost everything, gained everything and become the bearer of the fate of everything. In other words, the birth of a vessel that can be adapted to the poison of the stars. This is nothing less than what you were talking about earlier when you said that the world would regain its ability to circulate. This is our ultimate goal.

　Apparently, if he had been completely successful, that would have saved the world.
　But it seems that they couldn't reach one more step.
　Seeing the frustrated look on Mr. Di Prakula's face, I understand it.

''Let's move on to the next story. The experiment with the Vessel that Can Adapt to Demonic Poison was not so bad. The experiment on the Vessel of Adaptive Demonology was not so bad. There was only one problem with this experiment. The only problem with this experiment was that before the vessel was able to grow and perfect itself as a vessel that could adapt to the evil influence, its spirit had reached its limits. Therefore, we had a deal with the world to bring in someone with a strong heart who could become a vessel capable of adapting to the demon's poison.

　Then he pointed to us siblings lined up in a gym seat.
　So I slowly crunch the story and report back to them on what I understand now.

'I'm starting to understand most of it. So that's why Yotaki and I were called in. ...... To make us the new 'vessel that can adapt to the demon poison' that I just mentioned .......

　As I pieced together the numerous pieces of information, I came closer to a single picture.
　But there was much dissatisfaction in that picture.

'So now we're going to die once?　I don't mind, but as for Yotaki--
No, that's not true. You are already dead, and you have paid the price.
What?

　In some cases, I questioned him with enough enthusiasm to break off negotiations here, but he simply replied that he had nothing to worry about.

I was surprised to learn that ...... is a special being chosen to be the savior of the world's bargain. It's a good thing that you've been chosen to be the savior of the world. We can use the ability to circulate the demon's poison right away.
'Now we are ......?　But why ....... As I said earlier, you have to sacrifice a lot of things ......
Hmm. The first condition is that you go through death and give up being a man.

　Dead and no longer a person ......?

　But of course I have no memory of such a thing.
　There is a hollow clay doll lying in front of me now. I'm going to be the same as that one, but I don't feel like that at all.

"Perhaps, but ...... the two of you have lost your lives in your original world forever.
　You can never return. You're not going to be able to get your hands on any of them.
　That is what the world has judged.

　For my confusion, Mr. Diprakra spoke his own thoughts.

　--I'm as good as dead now?

　That overly cursory explanation further accelerates my confusion.

''Well, um, I'll check ....... Are we never going to be able to go back to our world again ......?
He guesses he cannot return. After all, when you summoned the lads, your "deal with the world"...
　The 'Price' of summoning Aikawa Yotaki is 'The Crisis on This Planet'.
　The 'price' of Aikawa Uzumi's summons was 'Aikawa brothers and sisters will live in this world permanently'
　-- that's what was decided. There were many candidates for the 'compensation', but the three of us decided on it after consulting with each other.
......!

　I'm speechless.
　The word 'cost' is too disturbing.
　And even more than that, the word 'deal with the world' is too unclear.

　I've managed to fool myself up to this point, but at last, I can no longer follow the conversation completely, and I turn my eyes to Yotaki next to me.

　Yotaki noticed my gaze and turned his face to me. On top of that, I nodded strongly and deeply. From that Yotaki, it seems that this story is trustworthy.
　With that alone, I trust Mr. Diprakra-san - and in order to keep up with the story, I'll be patient and ask for more details.

'Mr. Di Prakula, ....... Can you tell us more about that 'deal with the world' thing? I understand the importance of that. However, I've been wondering too much about that one word for a while now ....... I feel like if you don't understand that, you won't be able to get the next thing in your head: ......
I suppose. That's what you're going to say here. Don't worry about it. You have listened to me so patiently, and I thank you for that. Thank you, Cuirinha.

　Apparently my inability to understand certain words was factored in. Mr. Di Prakula praised me for not breaking my story, while stepping back and tapping his staff on the ground.

''Let's move on to explaining the 'deal with the world' once and for all here. If you understand this, you should be able to understand the details of your mission and your sister's illness correctly. So...

　With the movement of his staff, the small country of dirt that had been unfolding on the ground all crumbles back.
　Then the Sith who had been waiting in the rear leap forward.

'It's my turn to be the best at 'dealing with the world'!　Unlike the old man there, you can rest assured that my story is easy to understand!　I'll make you understand it in a hands-on format, chutzpah!　These things are usually pretty obvious when you use them!

　The conspicuous Mr. Sith had been waiting for this time to come, and he seemed very proud of himself and patted himself on the chest.

　He liked Sis-san's personality itself, but in a serious matter, he was a bit uneasy about it.
　However, Ms. Diprakra didn't seem to be talking. She seems to be the right person for the job, so I decide to listen in silence.

''Hmph. The first thing I want you to hear from Kanami is that she received it from my Lord and made Yotaki understand in an instant - this one word.

　Coughing like Diprakra-san, Sith-san coughed and collected it before speaking.

''-- There's no need to think hard about 'dealing with the world'. The point is, it's 'something like magic'.

　However, that one word was a bit far from what I was expecting.

　Something like .......
　It's too vague .......
　If you're willing to be that vague, there's something cooler out there.
　'Old magic formula', 'pseudo-magic', and many other things .......

　I'm not sure that my frustration with this is conveyed to Sis-san, and she proceeds to speak with confidence.

''In other words, with 'something magical', we summoned Yotaki and Uzurinami from another world!　To put it in more detail, I guess it's just a unique rule that doesn't exist in your world, but exists in our world. At a certain temperature, things burn and freeze. People are born and die. Like that kind of thing, limited to this world?

　I suppose he was referring to the laws of physics and the natural order of things.
　When I was told this much, the image was unwillingly solidified. In short, it's the system of 'something magical' in games and novels.
　Sure, it's easy to understand without going around, but .......

'Whatever. You give 'something' and you get 'something'. That's 'dealing with the world'. But you can't just get 'something' and you can't just lose 'something'. It is always an exchange. It is axiomatic that this is the case. In this world.

　After that explanation, Sith-san stepped forward and held out his right hand to me, who was sitting in the gym.

'And this 'deal with the world' is kind (...). For the record, you can trade anything for anything, and there's a lot to be gained on both sides. ...... for example, give me your time. Just give me your hand.

　--The world is kind.

　I didn't expect that word.
　To me, the world is a hard and demanding place.
　I've never felt kindness in my entire life.

　So, with doubt, I sat down and reached out my right hand.
　Then I put it over Sis's hand.

'I'm not lying. The world is kind. ...... Now I gave 'my time and hand' and you got 'your time and hand'. Hey, do you think you're missing out?　Do you feel like something was taken from you or lost?

　Staring straight at Sis, she confirms the meaning of the word.

　Our palms make contact with each other, and every cell of skin feels her smooth skin. And then the heat spreads softly. It gets hotter, even though neither of us has a particularly high body temperature. Perhaps both she and I are feeling something more than our true body temperatures. The act of giving each other that heat and building each other up is very reassuring. The human touch acts on our hearts, making our hearts leap and--and I'm sure it's not the only one.

　Nope.
　Halfway through, I realized that this was different.
　I'm simply too close to Sis-san. The throbbing is probably due to the fact that I have an overly well-groomed face in front of me that I would metaphorically describe as beautiful at first glance.

　I hide my agitation and try to be very calm and give her the answer she might be looking for.

'Well, um ...... both are warm. I'm glad for both. They both got it. Is that what this is about?
Happy?

　Just then, the beautiful woman in front of me tilted her head slightly.
　And in the next moment, her face turned red. Immediately, Sis-san shouted the rest of the explanation quickly, as if to deceive her.

''--That's right!　Like this!　It's the way the original 'deal with the world' was supposed to work, with both parties happy!　Because the world likes gain, not loss!　I love that it's an equivalent exchange, but inflates the value!　Because this world is alive, too!　Even the world instinctively wants to be strong and big, and it wants to be happy, just like everyone else!

　Anyway, it was clear that he was trying to shout loudly and blow off the upset. Perhaps it was worth it, but his next words were quiet and had a lot of weight to them.

''-- Okay?
　This world is always eager to negotiate with someone else.
　Particularly, it prioritizes negotiations that benefit everyone.

　With this story, that seems to be the most crucial part of the story.
　With a look of finally being able to say the crux of the story, Sis let out a big sigh, "Huh ......," and took her hand off me, distancing herself from me and inviting us to relax.

'In light of those things, feel the world ....... You can definitely do it. Because the two people who just got called up are the ones who have the freshest sense of 'demon poison' in the world right now. Moreover, they are the ones who are recognized to be the most able to adapt to the demonic poison. You will surely feel closer to the world on the ...... 'other side' than we, the apostles.

　Sis-san then spread her hands out as if to touch the air.
　The air flowed softly with her movements.
　A very clear and delicious air--.

"First of all, I'll give you a cupful of 'demon poison' here, and then I'll get 'another power' - 'power for you'. I don't mind trying things.

　The words caught our attention and we stood up.

　There was a lot of doubt in my mind, but I still knew that the woman in front of me was pure of heart. I'm not telling a lie. It's probably true that this has something to do with Yotaki's illness. It's worth a challenge for me just to be sure of that.

　Thus, in order to live up to Sis-san's expectations, the brother and sister take on the challenge of 'trading with the world' for the first time at the same time.

　At that time, I still couldn't swallow the explanation, and I had a look of uncertainty about whether I could do it or not - Yotaki next to me had a cool profile that said he already knew everything.

　What I remember is the days of competition in my former world.
　It was always the same for us siblings.
　It was the same when we did our first 'tear-jerking training'.

　When we challenged the same thing at the same time, there was a clear difference in our talents.
　My older brother Uzumi would fall behind his younger sister Yotaki, and I would always lose.
　I would surely lose.

　It was meant to be.