"Soap, huh..."
After finishing his bath, Jin was relaxing in a yukata.
He had taken a keen interest in the soap provided at the guest house. It had a good lather and a pleasant scent.
Although Jin had created many things, he had never made soap. At most, he had popularized the use of Rita fruit as a substitute and suggested using baking soda to help lift oil stains.
He knew that soap was made from fats and alkalis, but his knowledge ended there. Back at the orphanage, one of the other children had tried to make some, but Jin had been too preoccupied with his own projects to help, leaving him without any detailed knowledge of the process.
"I wonder if the man known as the magus was a specialist in chemistry," Jin mused.
He made a mental note to acquire several bars of the soap before they left.
"What about the bicycles, though?"
Just then, Elsa and the others emerged from the bath and joined him.
"Oh, those look good on you."
They were all dressed in yukatas. Seeing them in clothing he didn't encounter every day felt quite refreshing.
"Hehe, it's been a while since the Summer Festival in Kaina Village," Elsa said.
"This is such a fun outfit!" Hanna added.
When they opened the sliding doors facing the garden, they found a veranda where a cool breeze drifted in. It felt wonderful against their skin, which was still warm from the bath. Saki sat to Jin's right on the veranda, with Elsa to his left and Hanna settling onto his lap.
Jin caught the lovely scent of soap from the girls and found himself taking an appreciative breath.
"Onii-chan?"
"Ah, right... You all smell very nice, like soap."
"Yeah! It felt really good!" Hanna chirped.
"Mm. I want some," Elsa murmured.
"Yeah, let's buy some later."
"That's a great idea!"
Everyone was in agreement regarding the soap. After cooling off for a while, they resumed their earlier conversation.
"Regarding what we were saying earlier," Elsa began, "I thought that if he could make a bicycle, he must have known more than just chemistry."
"Yeah, I see your point, Elsa. But I realized something while I was looking over that bicycle earlier."
Elsa looked at him, her expression puzzled.
"The level of fidelity in the fine details was actually quite low."
"Wait, Jin, really?" Saki asked, unable to stay quiet.
"Yeah. The way the spokes were attached was a bit strange, and the same goes for the brake pads and how the levers and wires were installed."
"You can tell all that just by looking?"
"He was likely a chemistry specialist who maintained his own bicycle—I get the feeling his mechanical skills were roughly at that level."
"Hmm, as expected of the Magi Craft Meister," Saki said, impressed.
"You all used the soap, right? Being able to produce something like that suggests a strong background in chemistry. On top of that, I suspect he was also well-versed in anatomy."
"Why do you think that?" Elsa asked.
"Remember when I repaired the automata named Akitsu? It’s the impression I got from seeing how the skeleton and muscles were attached."
"That makes sense," Elsa said.
"Wait, what do you mean?" Saki asked.
"Saki-nee, human muscles are attached at a slight angle. That's what allows us to twist our arms and legs."
It was a highly simplified explanation, but the quick-witted Saki understood immediately.
"I see. That makes perfect sense."
Jin then noticed that Hanna had gone quiet on his lap.
"Ah, it looks like Hanna fell asleep. Let's lay her down quietly on a futon."
"Mm, that’s for the best."
With that, they all retired to their respective rooms to rest.
While Jin was eager to see the northern lands, there were still many things worth seeing in the capital. He decided they would stay for at least three or four days to explore Miyako and its surrounding areas.
Their guide was, of course, Mii. Despite her youth, she was remarkably knowledgeable and could answer almost any question about the city and its culture.
"That building is the oldest in town, though it's been renovated three times. Only the foundation and the base remain as they were originally."
"This is the Central Library. It has the largest collection of books in the city. You're free to read them here, but borrowing them is strictly prohibited."
"This is the National Park. It has an attached botanical garden where about half of all the plants found in our country are grown."
"And this is the Museum. It displays tools and items that are no longer in common use."
There were many interesting sights, and the first day ended after they had visited only four locations. Saki was most interested in the library, while Jin and Elsa preferred the Museum. Hanna also took a liking to the library.
"Why don't we have a day of free time tomorrow?" Saki suggested after dinner. It seemed she wanted to delve into the books at the library.
"Onii-chan, I want to read some books too!" Hanna chimed in. Apparently, she had already read most of the books back at Nidou in Kaina Village.
However, even if she had read them, many were advanced texts on mathematics or magic that she couldn't yet fully comprehend. Still, Jin thought it was excellent for someone her age to show such an interest in learning, so he agreed to Saki's proposal.
Even though they were called books, each volume was only about a hundred pages long and consisted mostly of handwriting, so they didn't contain an overwhelming amount of information.
"With Aaru's processing power, she could probably memorize about a hundred books in a single day," Jin remarked once Mii was out of earshot.
Saki looked at him with a startled expression. "I-Is that so? I'm not sure if that's convenient or just terrifyingly efficient."
"I think if Jin-nii said the word to Chief Hiro, he’d let her memorize the books quite openly," Elsa added. Jin agreed; it would be better to make a formal request.
Regardless, it was decided that Saki and Hanna would spend the next day at the library.
"Saki, I'm counting on you to look after Hanna. Hanna, be a good girl, okay?"
"Yeah, leave it to me."
"I will, Onii-chan! I love books!"
Aaru would be with them, and they were all wearing their Fellowship Bracelets, so Jin felt there was little cause for worry.
"What about meals? You can't get so absorbed that you forget to eat," the ever-fretful Jin warned.
Knowing Saki’s habits, Elsa interjected with a smile. "Jin-nii, we can just meet up and have lunch together. After all, you're the one who usually forgets to eat when you're focused on your work."
"..."
Jin found himself without a comeback.
And so, on April 10th, Hanna and Saki set off for the Central Library while Jin and Elsa headed for the Museum. Since both buildings were adjacent to the park and only about a hundred meters apart, the group walked to the library together first. At the reception, Mii spoke to the head librarian to ensure the group would receive every convenience.
"Jin, we'll see you back here at noon, then."
"See you later, Onii-chan!"
"Yeah, see you at lunch."
There was a small cafe attached to the library, so they planned to eat there. Once they parted ways with Saki and Hanna, Jin and Elsa were guided to the Museum by Mii. They had only caught a glimpse the day before, so they intended to take their time today. Mii’s knowledge of the exhibits was a welcome bonus.
"First, we have the transportation corner on the ground floor."
The room contained carriages, bicycles, rickshaws, and various palanquins. There was even a model of a horse representing its use as a draft animal.
"So horses really were used here once."
Jin hadn't seen many horses since they arrived.
"Yes. They used to be quite common, but about six hundred years ago, a horse plague broke out," Mii explained.
Equine diseases like paratyphoid, influenza, and encephalitis were common on Earth as well. It seemed a similar plague had decimated the horse population here.
"After that, rickshaws became the primary transport within towns, and bicycles took over for travel between them."
"Wait a moment..."
Jin noticed that the bicycles on display were fitted with rubber tires. When he pointed this out, Mii nodded.
"Yes. Bicycles with iron wheels are the older style, while the newer ones used rubber. However, once the supply of replacement rubber tires ran out, the newer models could no longer be used."
Hearing this, Jin realized it was the perfect opportunity to ask the question that had been weighing on his mind.
"I have a question for you, Mii."
"Yes, what is it?"
"Where exactly were these bicycles and rickshaws manufactured in the first place?"