"Ah, it stings a little."
Reinhard let out a soft sigh as he soaked in the hot springs at the Mansion.
Having returned from their excursion to the sea, the group was washing away the salt and stickiness of the ocean breeze. Though the sun was still high, they decided to indulge in the baths.
The facility featured newly added open-air baths, strictly separated by gender. The rock basins were constructed from granite quarried right there on Hourai Island, and they overflowed with a constant stream of fresh water.
The water for these open-air baths came from a different source than the indoor ones—a simple spring containing sodium bicarbonate that was exceptionally gentle on the skin. The temperature was kept lukewarm, making it comfortable even for those with mild sunburns.
While a severe burn could be easily cured with magic or recovery medicine, their skin wasn't in such a state yet, so no one had requested treatment. Still, Jin remained ready to provide medicine should any of the women ask for it.
"This feels wonderful, doesn't it?"
"It certainly does. Hot springs really are marvelous. I wonder if we could find one in Banne?"
"I've heard that if you dig deep enough, you can find a hot spring almost anywhere."
These voices belonged to Berche, Saki, and Elsa, respectively. They were soaking amicably in the women's open-air bath.
Berche had been hesitant at first, feeling a bit exposed in an open-air bath, but once she entered the water, the sense of liberation was so pleasant that she found herself completely relaxed.
"Still, every time I see them, I think Madam Reinhard's breasts are just unfair. I wonder what's even inside them," Saki remarked.
"Um... I believe it is fat and mammary glands," Elsa replied.
Saki blinked at the blunt, scientific answer. "Fat? Mammary glands? What are those?"
"Fat is essentially lipids. Mammary glands are the secretory glands that produce milk."
"Secretory glands?" Saki tilted her head, confused by the technical jargon Elsa was using so casually.
"Elsa, that's amazing! You've certainly been studying hard!" Berche exclaimed, genuinely impressed.
Saki sighed. "Does Jin teach you things like that as well? Just who is he, really?"
"Jin-nii is Jin-nii. I cannot say more than that. You should ask him yourself for the details."
Meanwhile, in the men's bath, Jin and Reinhard were having their own conversation. Since the two baths weren't adjacent, their voices didn't carry, and there was no risk of accidental peeking.
"If we're looking for the right time for Elsa to return to the Empire, I suppose the Technology Expo would be the best opportunity," Reinhard suggested.
"The Technology Expo?" Jin asked, prompting his friend for a more detailed explanation.
"The Technology Expo is a grand event where engineers from within the Shouro Empire and from nations we have diplomatic ties with gather to showcase their latest achievements."
Reinhard explained that the term "engineer" wasn't limited to magi engineers. Alchemists, ordinary shipwrights, and even architects participated. Naturally, various artisans and craftsmen were present as well.
"That sounds fascinating. When is it held?"
"The dates are fixed—three days starting from the Summer Solstice. It's also where official certifications, such as the title of Magi Engineer Maestro I mentioned before, are awarded."
"I see... That doesn't leave much time."
Seeing Jin sink into thought, Reinhard offered a word of caution. "However, there is one thing to consider. You'll need a solid justification for why you kept the fact that you were protecting Elsa and Mine a secret for so long."
"Ah, right..."
At the very least, it would seem unnatural that they hadn't mentioned anything while they were in Loizart, the capital of the Shouro Empire.
"There's a risk that some might suspect you abducted them for your own ends. Mostly the more reactionary, old-fashioned nobles," Reinhard added.
"I see..." Jin felt immensely glad he had consulted Reinhard. Having a friend capable of making such political judgments was an invaluable asset.
"I'll have to discuss this with Laojun as well..."
While it was a thorny problem, Jin was determined to find a solution.
That evening, Jin served rice for dinner, which was met with general acclaim.
"Hmm... When cooked properly, nogi—no, rice—can be this delicious."
It seemed the palates of the Shouro Empire leaned toward flavors similar to Japanese cuisine. Jin found that fact quite comforting. Conversation bloomed over the meal, and the night deepened in a warm, harmonious atmosphere.
The following morning, after breakfast, Jin gave them a brief tour of the laboratory. While Berche remained relatively composed, Reinhard and Saki looked around with eyes sparkling with unbridled curiosity.
Unexpectedly, Berche, who had seemed the least interested in technical matters, spoke up about one thing.
"Jin-sama, about the futons you provided for us... what is the material? I would very much like to know."
"Oh..." Jin hesitated. He wasn't sure if telling her they were made from the silk of Ground Caterpillars was a good idea. To gauge her reaction, he decided to ask a question first. "Berche, I believe most of the clothes you're wearing are made of silk. Do you know how that silk is produced?"
Because he was a bit flustered, his tone came out slightly formal, but Berche didn't seem to mind.
"Yes, it is the thread produced by 'Thread-worms,' is it not?"
Jin pressed a bit further. "Does the fact that the thread comes from an insect bother you?"
"No, not particularly? We use the hides of magical beasts for clothing and shoes all the time. I don't dislike insects—well, as long as they are pretty ones like butterflies."
Relieved by her answer, Jin decided to satisfy her curiosity. "I'm glad to hear that. The material for those futons is silk produced by Ground Caterpillars."
"Ground Caterpillars?" Saki was the one who reacted first. "Jin, do you know about Ground Caterpillars? Wait... are they actually here? They're a species of magical beast thought to be extinct."
"Yeah, I'm aware. Actually, a great many of them live beneath this island."
"Whoa! That's incredible! Take me there! I have to see them with my own eyes!" Saki pleaded excitedly.
However, Jin had harbored a bit of a phobia toward them ever since one had climbed on top of him during a previous visit to the underground.
"Well, eventually... You see, Ground Caterpillars are sensitive to light. They run away as soon as it gets bright."
He used that as a temporary excuse.
"The golems can move even in total darkness, though."
"I see. That's a shame. I suppose it'll have to wait, then. There's no point if I can't actually see them." Saki looked genuinely disappointed, but she quickly shook it off. "In that case, show me the rest of the facility!"
They toured the workshop, the research rooms, the library, and the warehouse. The crowning achievements, however, were the cold storage room and the freezer room.
"Hmm... Looking at all this again, I can only say it's truly magnificent," Reinhard said, momentarily speechless.
As for Saki, she turned to Jin with a look of pure longing. "Jin... I want to live here."
"I don't mind."
"Eh?"
Originally, this laboratory had been built by the Predecessor Magi Craft Meister, Adriana Barbora Tsetse, with the dream of making it a holy land for magi craft. While those driven by ambition or personal greed were unwelcome, Jin had no objection to hosting those who shared the same aspirations.
Saki was stunned by how easily he had given his consent.
"Provided you can keep this place a secret from the general public, of course," Jin added.
"Y-Yes, of course! I promise! Jin, thank you!"
On this day, the population of Hourai Island increased by one.
"Jin-nii, what about me?"
Unable to stay silent any longer, Elsa asked while tugging on the hem of Jin's shirt.
"Hmm? Elsa, you've been a resident here for a long time now, haven't you? You're my sister figure and my disciple."
When he said that, Elsa's cheeks flushed a faint shade of red.
"My, my, Elsa, how wonderful for you," Berche teased, noticing the reaction.
"...Yes," Elsa whispered, her face turning an even deeper shade of crimson.
"Ugh, damn it! I want to live here permanently, too!" Reinhard shouted.
"Dear?" Berche gave him a sharp, warning look that immediately silenced him.
"Haha, Reinhard, you're welcome to visit whenever you like," Jin said, trying to comfort his friend. Reinhard's spirits instantly recovered.
"Is that so! Ah, it really pays to have good friends!"
With that settled, the group gathered in the dining hall on the first floor to discuss future arrangements with Laojun.
"We shall provide you with magic tools that serve as permits. I will adjust the Warp Gate to activate only when it senses their presence," Laojun stated, outlining the security protocols. "The relay station, Shinkai, will perform a secondary check. If anyone other than Saki-sama, Reinhard-sama, or Berche-sama attempts to pass through, Shinkai will destroy the Warp Gate."
"Th-That's a bit terrifying," Reinhard admitted. He could imagine the consequences; while he didn't know exactly what "Shinkai" was, the idea of being stranded at a relay station or worse was chilling.
"May I truly come as well?" Berche asked.
Jin nodded. "Of course. You're Reinhard's wife. I want you to be there to support your husband."
"Jin-sama, thank you."
With a solemn vow never to reveal the secrets of Hourai Island to any outsider, a group that could truly be called the "Hourai Island Family" was born.