Chapter 43
A week after I sent four structural-color gremlins to Tokyo Magic University, a letter of thanks arrived, jointly signed by the professors.
For every research team that had been dying to quantify mana, the mana meter was practically a divine artifact that had suddenly dropped from the heavens. Apparently, a waiting line formed just to use it, and people were fighting over turns. The researchers, delirious with joy, forgot themselves in the festivities, while Professor Ōhinata, who had ghostwritten the collective letter of thanks, apologized for how late it had arrived.
When people praise me that highly, my nose starts growing like a tengu's. I really hope you use it as much as you can. But it's incredibly hard to make, so take good care of it, okay?
The first research project to use the structural-color gremlin was the establishment of a new system of units.
Now that the mana meter was complete, determining the unit came before anything else.
For length, there was the meter.
For weight, the gram.
So what about mana?
The professors held a heated debate over the unit's definition, but ultimately decided to take the middle ground between theory and reality.
They used the structural-color gremlin mana meters to measure the mana reserves of a randomly selected thousand people. The most common amount of mana held almost exactly matched the one millimeter indicated by the 400 nm structural-color gremlin.
From this, the amount of mana that caused the scale to change color by one millimeter when touching a 400 nm mana meter was established as the basic unit of mana: 1.0 Kenshi. In other words, 1.0K.
An ordinary person's mana reserve is about 1K. Easy to understand.
The name is easy to understand, too.
Since mana is “wisely seen and established,” it was called “Kenshi.”
Wow, that's a great name for a unit!
Could it have anything to do with my name being Dairi Kenshi!?
In the section about the unit system in the letter that came with the university's thanks, there was a doodle of a little stoat sticking out its tongue and winking, so it was definitely intentional.
That mischievous stoat really got me. Instead of using my name directly, it changed a character and made it sound close enough—that sly little touch was clever. Did you think I'd be embarrassed if you used my name as-is? You were right!
But I don't hate it. When a creator's name becomes well-known, it visibly changes how well their work sells. If I think of it as my pen name becoming the name of a new unit, it's totally fine. What a nice surprise, Professor.
Looking at the graph of the mana reserves of a thousand ordinary people attached to the letter, I could really see just how much mana I had.
My current mana reserve is 6.6K.
The fire lizard had 44–48K, so taking into account how much I lost when I embedded the fire-lizard gremlin in my left hand, it seems I originally had a little over 50K.
What Hiyori once said—“Dairi has a lot of mana”—had been true.
For reference, Professor Ōhinata has 120K.
The Fire-Bearing Witch, the pinnacle of humanity, has 200K.
The future-seeing mage had 5,100K, the lowest in the witches' gathering.
Apparently the Blue Witch was at the top of the witches' gathering with 11,000K.
As expected, witches and mages are on a completely different scale.
With only 6.6K mana, I can't use the Eyeball Witch's familiar spell, so ever since I embedded the fire-lizard gremlin, I've carried around a familiar Hiyori summoned in my pocket. I can't use Ice Spear magic anymore either, due to insufficient mana.
Still, with 6.6K I can cast the core spells of fire magic and freezing magic two or three times, so although things are less convenient than before, I'm doing reasonably well. 6.6K is still a lot of mana. I'm in the top ten percent of humanity.
At the end of the letter, which conveyed the joy and excitement of the Magic University, there was a slightly frightening research finding.
According to research the Department of Magical Medicine conducted immediately using the mana meters, fainting from mana depletion apparently causes a slight decrease in one's mana reserve. Each episode of fainting reduces it by roughly 0.05–0.1K.
You can't use magic when you are clearly short on mana. However, if you try to use magic when you're just a little short, your maximum mana is automatically shaved down to make up the deficit, forcing the spell to activate. Then your mana reaches zero and you faint... That is apparently how it works.
There had already been a theory that fainting from mana depletion reduced one's maximum mana, but the decrease was so small that it was impossible to tell whether it was due to aging, measurement error, one's physical condition, or any number of other causes.
After the Mushroom Pandemic, fainting from mana depletion became taboo throughout society. Now there was yet another reason to avoid it.
Thinking about it now, that's terrifying. Apparently Professor Ōhinata, for one, used to faint from mana depletion all the time before the pandemic. It wouldn't be strange if the professor had lost two or three K of mana. That's insane.
The fact that people used to do something that dangerous without a second thought really shows how ignorant humanity was about magic back then. Knowledge is power.
Whenever I hear things like this, I really feel that there must be countless important magical truths we still haven't noticed, even though we should have.
It has only been about five years since humanity learned about magic. I—we—have only just reached the edge of the abyss of magic. All we can do is conduct steady research and keep trying things out.
Now then.
It was a day in early spring, when the cold and warm days alternated.
I was at Hiyori's house, helping her choose the color of the feathers of a pouch sparrow she planned to get soon while we looked through a catalog together, when my stomach suddenly started hurting.
I clutched my abdomen as it suddenly began to throb, and panicked.
W-what's going on? I don't remember eating anything dangerous.
I waited for the pain to subside for a while, nodding along to Hiyori's conversation, but instead of going away, the pain in my abdomen started getting worse and worse.
Damn. This is the kind of thing that needs medicine.
"Sorry to interrupt. Hiyori, do you have any stomach medicine?"
"Hm? I have some herbal medicine. Is it your stomach?"
"Yeah. My stomach... hurts like hell...!"
"...Hey? You're covered in cold sweat. Are you okay? Can you stand? Hey!"
I staggered when I tried to stand, and Hiyori caught me.
This is bad, bad, bad. The pain keeps getting worse!
"Hurry... the stomach medicine..."
"This isn't something medicine can fix! An ambulance—wait, those are gone now, damn it! We're going to the hospital right now. Can you walk!? Are you all right!?"
"The hospital? No, I hate hospitals. I'll cure it with medicine..."
"That's why medicine won't cure this! Can't you tell that yourself? You're sweating buckets. Your complexion is awful, too!"
"I don't want to go to a hospital. Doctors ask all those questions..."
"Is this really the time for that, idiot!?"
Hiyori finally lost her temper and, having had enough, forcibly picked me up and carried me horizontally.
Whoa, she's incredibly strong...! It felt like being firmly carried by a sumo wrestler or a professional wrestler. The stability and sense of security were amazing.
Still carrying me, Hiyori hurried to the entrance, slipped on her shoes, and went outside. She shifted me into a firmer hold and spoke in a dependable, gallant voice.
"I'm going to speed up. Hold on tight. Boil, my blood."
After casting a self-enhancement spell, Hiyori took off like a bullet.
Hiyori tore through the city like the wind, running incredibly fast without jostling me at all.
Ugh, a hospital. I hate this so much. I had gone to the trouble of stocking medicine at home because I didn't want to see a doctor.
But even while I was being transported at high speed in her arms, the pain in my abdomen kept growing, surpassing even what I had thought was the limit.
I cried.
It hurts. It hurts so much.
I hated doctors, but if they could free me from this agony, I didn't care what happened anymore. Somebody help me!
While I sobbed, Hiyori swiftly crossed the city and carried me into a huge hospital in Chiyoda Ward. From what I heard on the way, this hospital had the best doctors and offered the greatest privacy.
"I'm the Blue Witch. Send out your best doctor immediately!"
At that single commanding declaration, the hospital erupted into a commotion like a hornet's nest had been kicked. The chief physician hurried out and escorted us farther inside.
In an examination room with clean beds and desks, I underwent a rapid-fire medical interview and palpation with Hiyori at my side. I hate this unmistakably hospital-like smell of disinfectant. Could they cure me and send me home soon? Or maybe give me perfume that smells like burning iron, charcoal, and wood.
After finishing the examination, the doctor gave my lower abdomen one final hard push, making me burst into tears, then nodded.
"It appears to be appendicitis."
"Appendicitis...? Is that a disease that kills you?"
"I'll do anything. Doctor, save him."
"Appendicitis is what people commonly call an inflamed appendix. Even in this day and age, it's easily treated with a simple operation. You won't die."
"The appendix..."
The appendix.
I had heard of that, hadn't I?
I think it was famous for being a simple operation.
So I'm not going to die? Even though my stomach hurts so badly I feel like I'm going to die?
Oh, thank goodness.
Apparently, I only feel like I'm going to die. I won't actually die.
"Good, it's only appendicitis. Well, not good, exactly."
I heard Hiyori's blatantly relieved voice behind me. I was relieved too, but the doctor hesitated slightly before adding something.
"Normally, we would proceed directly to surgery, but we recently introduced a new magical diagnostic method. If you don't mind magic, would you be willing to undergo it, in order to avoid even the possibility of a misdiagnosis? Its safety has been confirmed."
"Absolutely. Please do it."
For some reason, Hiyori answered immediately instead of me, the patient.
I mean, I didn't mind. If it increased the odds of avoiding a misdiagnosis, go ahead.
"And while you're at it, check everything that's wrong with him."
"Understood. Then after the operation, we'll conduct as thorough an examination as possible while monitoring his recovery. But first comes the magical diagnosis. Ishiya-kun, please explain it."
The doctor spoke to a young man standing in the corner with a chart, then stepped back as the young man came forward instead.
He gave a slight bow and began his explanation.
"I'm Ishiya, a magical physician.
"I'm about to use a bypass incantation for the Eyeball Witch-sama's clairvoyance spell. I'll use three types of gremlin and see through your body three times, changing the output each time. You can think of it as something like an X-ray examination.
"The difference from an X-ray is that we can't develop photographs, which makes it difficult to explain the results to the patient or anyone accompanying them. There is also zero radiation exposure.
"Do you have any questions?"
We shook our heads.
It was reassuring that X-rays had been introduced. Professor Ōhinata, thank you so much for inventing the bypass incantation. Thanks to you, it looked like I was actually going to get an X-ray examination.
After confirming our consent, Doctor Ishiya nodded, set his chart aside, and picked up a wand fitted with a small gremlin bearing a sticker marked ①.
"You may leave your clothes on... Excuse me, but could the Blue Witch-sama please move over here? If you remain in that position, I will see through the witch as well."
Hiyori flinched slightly and quickly moved to the side.
This spell seems like it could be abused for some pretty lewd voyeurism. Well, I suppose abilities and spells with naughty applications must be a huge help to doctors, so maybe that's just how it is.
"Would gouging out both eyes make me unable to see things that shine like the sun instead of lies?"
As instructed beforehand, the same spell was chanted three times while he switched wands.
Judging by the gremlins' size and shape, the output was probably 0.7 times, 1.1 times, and 1.5 times.
Huh. Not bad. I would have liked to praise the ingenuity of changing the output so precisely to alter the depth of the scan, but I couldn't speak through the agony, so could you operate already? I was getting nauseous, too. It felt like my stomach was about to spill out of my mouth.
The magical scan apparently also indicated appendicitis, so once I gave my consent, the operation got the go-ahead.
They quickly changed me into surgical clothes, put me on one of those wheeled beds for transporting patients that I had often seen on television, and carried me to the operating room.
I parted from the worried Hiyori in front of the operating room and headed into battle.
Five doctors in surgical clothing surrounded me. One briskly put an oxygen mask over my face, while another plunged a needle into my arm.
"This is an injection of sedative. We'll anesthetize you as well. You'll be fine. The operation will be over by the time you wake up."
A sedative and anesthesia? That's just knocking me out against my will, isn't it?
I don't like this. It's not impossible that this sleep could become eternal sleep.
I'm Dairi Kenshi! I can easily withstand――――
――――By the time I woke up in a hospital bed, it was all over.
Are doctors' drugs really this strong?
I couldn't resist at all. My consciousness just dropped away, plop, that easily. One-punch KO.
No way I could beat that, I thought, sinking into a sense of defeat. I blinked several times to clear my head, then spoke to Hiyori, who was sitting in the chair beside the bed.
"Good morning. How long has it been?"
"!? Dairi's awake! Thank goodness...! It's been about thirty minutes since the operation ended. You seem to be pretty sensitive to anesthesia. They said people usually wake up sooner, so I was worried."
"Oh, really? Good thing I didn't sleep forever."
"Don't say that. It's not funny."
"No, seriously. It was my first operation ever, after all."
Hiyori silently squeezed one of my hands tight.
She seemed to be squeezing pretty hard, but my senses were still slightly dull. There was still anesthesia in my system.
As the abdominal pain gradually set in when the anesthesia wore off, they kept it under control with painkillers, and I got through the first three days after the operation on an IV drip.
Apparently my hospital room was a VIP room. The Blue Witch had explained the situation while keeping various details under wraps, so there was no sign of anyone else during my stay, and it was as comfortable as could be.
They even changed my IV bag while I was asleep. I was being treated like royalty.
But on the fourth day after the operation, something intruded on my comfortable life.
The doctor who brought my first light meal after the operation—the chief physician who had initially taken my medical history—said he had something important to tell me.
As I paled and Hiyori stiffened with tension, the doctor said gently,
"Please don't worry. It's not bad news."
"What, good news? You startled me."
"Yes, it is good news. However, it may sound a little strange. While you were sleeping, we performed various health checkups and tests, and the results were..."
According to the doctor, I was apparently a pretty incredible human being.
I had known for ages that I was unusually dexterous, but now there was a certain amount of medical and anthropological explanation for it as well.
Humans evolved from apes.
But the truth was that we were still in the middle of evolving.
For example, there are rare people in the world with tetrachromatic vision. Ordinary people have trichromatic vision with three types of photoreceptor, whereas people with tetrachromatic vision have four types.
The number of colors a tetrachromat can distinguish is said to be anywhere from several dozen to a hundred times greater than that of a trichromat.
This was evolution in the truest sense, and tetrachromatic vision had no disadvantages. It could be called a complete upgrade over trichromatic vision.
Apparently my eyes had evolved as well. Extremely unusual tissue had been found around and inside my eyeballs. They couldn't say for certain, but it seemed my resolution had improved dramatically, allowing me to see things as if through a microscope.
Well, yes. These eyes are hereditary. My mother had good eyesight, and so did my older sister. Neither of them was as good as mine, though. It must come from my mother's side.
My heart was unusual, too. It only beat about once every ten seconds. In exchange, each beat pumped out a huge amount of blood. There were existing cases of this, and although it was unusual, it apparently posed no threat to my health.
Yeah, exactly. It's useful. Ordinary people's hearts go thump-thump, and the vibration travels to their fingers and makes their hands shake. Since mine only beats once every ten seconds, I can work with considerable stability.
Finally, my fingers were apparently different as well. They had a broad range of motion and were flexible, yet highly stable when held in place, allowing for delicate movements.
I knew that. I can bend all the fingers on both hands backward at once and touch them to the backs of my hands. I've never seen anyone else who could do the same thing.
"Does this mean you've mutated into a mage?"
Hiyori spoke in a voice that sounded somewhat hopeful, but the doctor shook his head.
"No, you are not a mage. We found no mutation in your vocal organs, and there has been no increase in your mana. Even after subtracting the decrease in maximum mana caused by the gremlin embedded in the back of your left hand, you are well within the human range. Your organs are quite youthful as well, but otherwise normal. It is an extremely unusual and exceptional case, but unlike a magical mutation, everything can be explained medically. You could say you represent one of the leading edges of the ongoing evolution of humanity."
"Huh."
I had already known most of what he told me, but getting a medical seal of approval made it sink in.
"I thought these eyes of mine were pretty darn overpowered, though."
"Overpowered...?"
"Ah, it's slang for special or abnormal..."
"I see. My apologies. I'm not very familiar with new words. The revolutionary evolution of your eyesight is extremely rare, but it isn't unprecedented when you look back through evolutionary history.
"For example, the evolution that occurred when living creatures acquired eyeballs was truly revolutionary. A structure that could only see flat images changed into one capable of three-dimensional vision. The evolution of the rear wall of the eye socket acquired by apes was revolutionary as well. Once a bony wall formed behind the eyeball, their visual vantage became dramatically more stable, giving them a clear, steady field of vision.
"The changes that occurred in your eyes are comparable to those great turning points in the evolution of vision... No, that's overstating it. Still, without a doubt, they are a wonderful step in evolution."
"Evolutionary history is amazing!"
Witches and mages have undergone absurdly drastic mutations, but I'm pure, genuine Earth-born evolution over here! Don't underestimate humanity's potential! Gahahaha!
"Oh, right. Why don't you get a health checkup too, Hiyori? They might find something strange about you."
"Ha! A health checkup would be pointless for a witch. I may look human, but I don't have a heart, and my core body temperature is below freezing. Even if they examined me, all they would find would be abnormalities."
"That's crazy. Your hands are perfectly warm, though. And you have a pulse."
I kneaded and squished Hiyori's hand, but it felt exactly like an ordinary woman's hand.
It made no sense how she produced that kind of power with this hand.
She looks like an ordinary beautiful girl at first glance, too. I don't get it.
While I examined Hiyori's hand, which was completely rigid and didn't twitch, the doctor smiled, told me to take care of myself, and left after saying I could be discharged tomorrow if my recovery continued to go well.
Honestly, when that terrible pain shot through my abdomen, I thought I was going to die, but somehow everything worked out.
I even gained a proper medical understanding of the source of my incredible dexterity, though I got the feeling he had explained it in very simple terms, so overall, I suppose this wasn't such a bad accident.
I'll be discharged tomorrow.
Once I get home, I'll have to take care of the fire lizard that I left unattended during my hospital stay while I work on my rehabilitation.