Since the King's declaration, Celeste's existence became public within the royal castle, and he'd adapted to living while traveling between Earth and Tusita, growing accustomed to both worlds' rhythms. Such a Celeste was temporarily assigned a room in the royal palace and told by the King to use it as the base for spacetime transfer gates from Earth.

  "If you keep appearing from various places, it'll trouble everyone working in the castle.

  The guard and such are lamenting their prestige is completely ruined."

  "That was wrong of me.

  But 'trouble'..."

  "It's fact. Suddenly a door appears in empty space, and from it emerges a highest-ranking noble...

  Don't you think that's bad for the heart?"

  "Like smoking behind the company building, badmouthing the president, when the man himself descends?"

  "...I don't understand half these words like 'tobacco' and 'president'...

  Anyway, please refrain from being so elusive as much as possible."

  "Understood. I'll do my best."

  "Is that something to say before the King?"

  Their eyes met, and both burst out laughing.

  Watching them with an exasperated look, Norgaar interjected.

  "Stop flirting, you two...

  Indeed, even as a Regis of the Regis-Basii royal family, not entering formally but appearing arbitrarily from within the palace doesn't set a good example for other retainers, Dad.

  Please exercise some restraint.

  It's natural the guard has complaints."

  Seeing Norgaar advising seriously, the two looked blank.

  "So he says.

  As expected of our reliable Guard Captain. Blunt advice without mercy."

  "Ah... our second son is so cold.

  This father is saddened, Your Majesty.

  Boo hoo hoo~"

  "Why do you two sync up perfectly at the wrong times?!

  Now, Dad! Enough foolishness and get to the Magic Ministry already!

  Mage Chief Nairan is waiting eagerly!"

  "Ah, right.

  Then let's take a gate from here.

  Celeste, departing!"

  "That's what I told you to stop doing!"

  Celeste had gotten tired of saying "transfer gate" each time and started calling it just "gate."

  "Sorry to keep you waiti—"

  "WHOOOOOAAA!!"

  "Wh-what?!"

  The moment Celeste opened a gate to the Magic Ministry's indoor training ground—his meeting place with Nairan—a tremendous cheer suddenly erupted from around him.

  "Did you see? No magical effect at all! Yet a gate!"

  "Given transfer magic's calculation formula and activation delay, that speed is abnormal!"

  "Ahhh I missed it! Regis Celeste! Please do it again!"

  "That's right! Please!"

  "Uh, well, the thing is..."

  Even Celeste was overwhelmed by the mages' pressing intensity when salvation appeared.

  "Everyone, enough! Is this the etiquette of court mages?!

  Bring the measurement devices! Both magical power and thaumaturgical power!

  Now, Regis Celeste. Once observation preparations are complete, please do it again!"

  ...Apparently not.

  After that, Celeste ended up repeatedly opening and closing gates, showing connections to various parts of the castle.

  "Can't you connect outside the royal castle?"

  "No, it seems it won't activate unless it's somewhere I know."

  "Ah, right. You haven't gone outside the castle yet, have you?

  Maximum transportable distance still unknown... noted...

  What about the gate connecting to that planet Chikyu?"

  "I haven't connected anywhere but inside my apartment... house on Earth.

  At first I thought the gate would only open at the wall closet, but after testing—"

  He paused briefly, but the mages were absorbed in writing and didn't seem to notice.

  "I could open gates to Tusita freely from anywhere inside the house.

  Unauthorized content usage: if you discover this narrative on Amazon, report the violation.

  Well, I haven't tested outside the house yet. It'd be terrible if someone saw."

  The mages kept writing, trying not to miss a single word Celeste said, but he could see they had to dip their pens in ink during writing.

  "Ah, right. I prepared this for today's tests...

  Everyone, would you like to try using these?

  Those pens look quite inconvenient."

  Saying this, Celeste pulled a ballpoint pen from his pocket.

  "May I? I'll use my duplication ability with this, so please observe."

  Another cheer arose among the mages.

  "Preparations complete! Go ahead, please!"

  'Nairan seems rather excited.'

  Not remotely thinking he was the source of this fervor, Celeste thought 'Mages probably write a lot for research, so let me prepare plenty,' and built a mountain of ballpoint pens on the nearby table.

  "D-did you see? From empty space, matter manifested one after another!"

  "Though it duplicated existing matter, that was..."

  "Again, neither magical nor thaumaturgical power detected...

  What is that power?"

  Celeste, feeling somewhat accustomed to the mages' commotion, picked one pen from the mountain and offered it to Nairan.

  "Here, please try writing with this."

  "Writing... is this a writing instrument?"

  "Yes. Ah, you don't need to dip it in ink.

  Remove that cap and just... yes.

  Won't everyone try it too?"

  The mages swarmed around Celeste as if they'd been waiting.

  Taking ballpoint pens in hand and observing intently, Nairan said almost shouting:

  "Wh-what is this...! Writing without dipping in ink, and this smooth writing feel!

  The ink is... I see, that black thing visible inside?"

  Hearing this, the other mages busily removed pen caps and test-wrote, raising cries of surprise.

  "That's right. High-viscosity ink stored in that tube flows out through the pen tip made of fine tubing.

  Inside that pen tip is a tiny metal sphere, allowing smooth writing—"

  "I see. Because it's high-viscosity ink, there's no need to wait for it to dry!"

  One mage shouted as if achieving enlightenment.

  "Correct. Well noticed."

  Though Celeste felt odd acting so pompously about something he hadn't even invented, he felt he had to explain what he knew or couldn't endure the question barrage.

  "But a sphere inside such a thin tube... ah, this is it!"

  One sharp-eyed mage identified the ball in the pen tip and cheered.

  "However, if this isn't a magical tool...

  This is the product of tremendous processing technology."

  Having calmed somewhat, Nairan gave a serious impression.

  "Well, yes, that's about right.

  I'm giving them all to you, so please use them together."

  Generously (though it only cost one ballpoint pen brought from Earth) saying this, the mages couldn't hide their surprise.

  "Is it alright? To receive so many?"

  "Yes. I originally prepared them for experiments, and they're cheap.

  Those pens must be inconvenient for shorthand and such?"

  "Then we'll take advantage of your words!"

  Watching the unhesitating mages, Celeste thought, well, that figures.

  These mages weren't so different from fictional ones, being people with insatiable thirst for new knowledge, so those pens would probably be treated as research materials rather than writing implements.

  After that, they conducted duplication experiments while varying samples.

  This was something Celeste himself wanted to verify.

  Duplicating Tusita materials that weren't from Earth succeeded without problems when he borrowed a pen from one mage.

  'Can living things be duplicated?'

  For that question, they tried using a butterfly-like insect the Magic Ministry kept for experiments, but this ended in failure.

  If living things failed, what about 'things that were living'? The opinion arose, and they tried with raw meat brought from the kitchen, but this too proved impossible.

  'But that chu-ru's material is meat... hm?'

  Suddenly noticing, he had them prepare 'cooked' meat to try, and successfully duplicated it.

  "...Things of biological origin can only be duplicated once they reach the 'processed product' stage.

  Honestly, that's complicated!"

  He muttered, but understanding such a law was certainly a harvest.

  Nairan and the other mages were joyfully writing something furiously.

  "However, Regis Celeste."

  "Yes?"

  "In that 'duplication' process, have you tried changing the original material's properties?"

  About to answer that wouldn't be called 'duplication,' Celeste recalled a fact.

  Indeed, even copy machines have enlargement/reduction functions.

  You can copy color as monochrome too.

  "That's a blind spot.

  But... sounds interesting. Shall we try?"

  While saying this, Celeste took one ballpoint pen, and though he thought chanting wasn't necessary, spoke aloud for the mages to hear.

  "Enlarge and duplicate to about 1 meter... huh?"

  It had indeed enlarged to about 1 meter as stated, but hadn't duplicated.

  "Wait, what did you just do?"

  "I just said—I tried to enlarge and duplicate, but this is what happened.

  Could it be I can't enlarge and duplicate simultaneously?"

  Celeste thought it a stingy ability, but Nairan didn't seem to think so.

  "That's amazing! Another ability discovered!

  You there, you measured that, right?"

  "Yes! As before, no power detected!"

  Thinking how diligent they were, he tried saying "return to original," but this also didn't work.

  "Once alteration completes, reversal seems impossible. Most interesting."

  'Entropy change?!'

  He retorted internally, but couldn't say it before Nairan, who was investigating the giant ballpoint pen with sparkling eyes.

  Telling himself that if questioned while only knowing vague general theory, what would he do, Celeste tried to say as little extra as possible.

  After that they tried making it smaller, duplicating already-altered things, and various tests, but altered things had their properties fixed there and could be duplicated as altered.

  "But this big ballpoint pen... what shall we do? Erase it?"

  Things duplicated on Tusita vanish when taken through gates returning to Earth.

  At first he'd been disappointed failing to multiply that robot model, but then decided he'd use it to dispose of troublesome materials like vinyl and plastic that Tusita couldn't recycle or decompose, produced from duplicates made here—so he thought he'd do the same with the useless giant ballpoint pen.

  "Erasing it would be wasteful!

  For disassembly research, this size is perfect!"

  Saying something outrageous, Nairan's face seemed to say, while behind her the mages nodded vigorously.

  "Well, if you say so, I'll leave it to you.

  However, be careful of ink leaks when disassembling.

  If it gets on clothes, it'll stain and won't come out even washing.

  Also, about that material...

  It's safe as is, but burning produces toxic gas.

  Be careful of that too."

  Just in case—or rather thinking it might become a serious problem—he warned them, and the mages again diligently wrote as if hearing profound wisdom.

  'Even warning them, there's always one idiot who spills ink on their clothes and proudly boasts "This is a badge of honor!"'

  ...He couldn't even imagine nearly everyone here would become that idiot.

  "Now... is this enough for experiments? I can't think of anything else to do."

  Celeste was getting ready to leave, but for Nairan that wasn't acceptable.

  "Um, besides that 'ballpoint pen,' do you have anything else that shows Chikyu's technology?"

  Apparently verification of duplication ability was sufficient, and now she wanted Earth-produced 'things' to examine thoroughly.

  "Let's see... what I have now is... hm?"

  The smartphone was bad.

  The cats' photos inside were risky(?), but messing with the battery causing an explosion would be worse.

  Thinking this while sticking his hand in his pants pocket, his fingertips touched something.

  Taking it out, ah, he remembered.

  The other day, returning from a drinking party, on a whim he'd stopped at a gacha shop, got this, tossed it in his pocket, and forgotten it.

  "What's that?"

  "Ah... this is, how to say... a miniature of Earth's musical instrument... a scaled-down model."

  "So delicate... perhaps an expensive craft item?"

  "No, just an industrial product."

  "Something so exquisite?"

  Watching the astonished Nairan over a cheap gacha item, Celeste—no, Amashiro—felt proud.

  'Well, saying Japan's miniature technology is world-class isn't an exaggeration~'

  This wouldn't be bad to give as a sample either.

  Thinking so, Celeste said to Nairan casually.

  "Then let's try duplicating and enlarging this too.

  First duplicate several... there.

  Next, to 'reall' size..."

  However, this time something was different from before.

  The enlarged guitar miniature flashed briefly—

  "Eh?

  Huh?

  Whaaaat?!"

  "Wh-what happened?"

  Surprised at Celeste suddenly shrieking after doing it himself, Nairan leaned forward.

  "Th-th-that is...

  Th-this...

  It-it seems...

  It-it became the real thing!?

  Huh, what's this? Whaaaat?!"