Before the Municipal Libraries of the Six Great Cities, the Grand Library of Chinzei

[Core Room]

"Marie-san, what's our next move?"

"The second wave of settlers is on its way, and the summoning of the municipal libraries of the Six Great Cities. That's the plan."

The Six Great Cities are special cities, independent of their prefectures, whereas government-designated cities are counted as part of their prefectures. In other words, Yokohama City is not Kanagawa Prefecture, but Kawasaki City and Sumō… Sagamihara City are. And yet the Kanagawa Prefectural Government Office sits in Yokohama all the same. Such is the way of this world.

"Among the special cities, Kyoto doesn't have a large central library, so we'll put it off for later. We'll make the larger libraries of prefectures and government-designated cities summoning targets too, and by stacking them up from the bottom, widest first, in good balance, they'll form the skeleton of the library dungeon. Cram small and mid-sized public libraries into the gaps, and it's complete."

"All at once is impossible, of course."

"Right. And as it happens, among the libraries that are summoning candidates for the moment, there's one with the largest footprint, about 100 meters square, that balances well placed on the ground. Whether it's that a government-designated city costs less than a special city or a prefecture would, or that being far off in Kyushu its name recognition is lower, wouldn't you know it, with our current stored energy it's one we can actually summon."

The fourth tier-group was five stories above ground, with a total floor area of 24,000 square meters. With this, the dungeon became a tower-type, twenty-six stories tall, stacked from the ground up in the order four, one, two, three.

[Before the Library Dungeon]

"Marie-san, so the entrance ends up on the southeast side."

Since it's dangerous for the Dungeon Master to go where adventurers also come and go, the Master stayed in the Core Room.

"The opposite of Iruma, which lies to the west. But the old Nakayama, that is, Sun Yat-sen, the highway that runs lengthwise through Adachi, lies in this direction, so in time it'll make a fitting orientation for the entrance. And the Imperial Library (i.e. the National Diet Library) we plan to summon someday, if anything, has its entrance on the southeast side too."

"I do know of Sun Yat-sen, as a matter of knowledge at least."

"Long ago, far off to the southeast, there was a dungeon called Nakayama Racecourse, a grassy place with horses, or so I'm told. The dungeon itself may well still be there even now."

It surely wasn't Sun Yat-sen. So thought the Dungeon Master, but in this world it must be so.

[Fourth Tier-Group, First Floor]

"Still, as always, you can't summon cooked food in the dining hall."

Marie was in the fourth tier-group; the Master, as ever, watched from the Core Room through a monitor.

"No, you can't. The hall on the south side, let's remodel that for the municipal assembly down the road. Broadly speaking, the first floor for public facilities and shops; the outer parts of the second and third floors partitioned into housing; the storerooms repurposed as warehouses."

"If we divide it up into ten-meter frontages, we can't fit all that many homes…"

"This being the world it is, for the time being even 3.6 meters will do nicely. I'd say we can pack in around a hundred and fifty units."

"Worse than rabbit hutches. The second tier-group was treated as temporary housing, so it passes there, but won't a revolution break out or something?"

"In this world that's simply how things are, so there's no problem. Add in the existing housing and it comes to about a thousand people; turn the whole hill into farmland and productivity works out to about that much as well, so I'd call it just right."

"You're not going to use the third tier-group?"

"Hmm. It's a university library, so I suppose it's for when scholars come, in the future. As a plan, anyway."

"Fields can only spread out across a plane, though."

"Right. According to the Encyclopedia Dungeonica, there's an account of supplying light to underground spaces to create forests. But this dungeon spends so much energy on maintaining the living environment that we can't afford that sort of thing."

"Won't commuting to the fields be a hassle?"

"Come next spring we'll build paddies on a grand scale from the foot of the hill, so over the winter let's summon several small libraries and place them around the hill. Ordinary buildings would do, but dungeon structures are more sanitary and sturdier."

"Even so, the farther out it gets, the harder it is to keep proper watch."

"That's just it. As things stand, the theoretical surveillance range from the rooftop is about 50 km; once this whole run of expansion is done it'll reach around 70 to 80 km. Of course, the security cameras' performance hasn't caught up, so in reality it's about 20 km. And say we summon a knight order for defense and send them racing out whenever bandits appear; the defensible range is half of that. Even so, race them a full day and they wear themselves out. That's where it becomes a question of automobiles or railways, but this dungeon can't summon those, and having Mint build them is a stretch."

"For that matter, we don't even have a knight order to begin with. Is there even such a thing as a knight Shiso?"

"Next will be summoning a military man, then. That said, one man alone can do nothing, so as for the knight order to place under his command, shall we have the magistrate find them for us?"