Crossover Shipgirls: Building a Dimensional Empire from Scratch

As the first human to set foot in the harbor—and in such an outrageous manner as traversing worlds—Setsuna became the center of attention for all the shipgirls in the Azur Lane universe.

Not only was the reception hall packed with shipgirls, but destroyer lolis crowded the doors and windows, craning their necks curiously to get a glimpse of him.

”Please enjoy.”

Belfast walked over, carrying a tea set. With a slight bow, she poured tea for Setsuna and the flagships seated around him.

She also placed plates of fruit, snacks, and pastries on the table before stepping back to the side.

Every gesture carried the poise of a perfect maid, though even she couldn’t help but sneak a few glances at Setsuna.

”Thank you.”

Setsuna took a sip. As expected, the head maid’s craftsmanship was excellent.

”We’ve heard the gist of the situation from Richelieu earlier.”

After brief introductions, it was Enterprise, dressed in a white naval uniform, who spoke first.

”You come from another world and possess the ability to pierce through dimensions. Can you tell us how that’s possible?”

”Is it related to Siren technology? There are rumors they’ve been conducting similar research…”

”No, just think of it as a superpower. I can open portals to different worlds, provided I can observe them.”

Setsuna thought for a moment before explaining.

”Oh…”

”Can you tell us more about your world? You must come from an extraordinary civilization.”

”What other worlds surround ours?”

The shipgirls’ interest was immediately piqued. They crowded around him, eager for answers like children waiting for a story.

”Sure.”

Setsuna waved his hand.

Swish!

The Hyperdimensional Star Map unfolded before them. Using the marked civilizations on the map, he began to explain one by one:

”Look here, this is the Azur Lane world, where we are now…”

”Above it is a world called Date A Live, home to Spirits who can use magic.”

”Next to it is the Honkai Universe, where they study Honkai energy and often engage in deadly battles with Herrschers. Over here is the Type-Moon Universe, where heroic spirits are summoned to fight. By the way, the King of Knights is actually a cute girl…”

”Spirits using magic? Of course—they can control time, summon things, and more…”

The shipgirls listened with rapt attention.

To shipgirls who had spent most of their lives at the harbor, these fantastical worlds were irresistibly fascinating.

Even Belfast, who was usually single-minded in her dedication to her work, paused what she was doing and quietly joined the crowd to watch.

”With this diplomatic interface, you can communicate with other worlds? Just like you did with Richelieu earlier?”

Enterprise moved closer to Setsuna.

She had heard of the Sirens researching some chaotic mirror-universe technology, but nothing as convenient as what Setsuna had demonstrated.

”Hmm… how about we contact someone else for a chat?”

Setsuna tapped on the Demon Slayer Universe.

Zzzt!

After a brief flicker of static, the screen revealed a tall, pale-skinned young man in a suit.

He had been working with some experimental equipment, but the sudden appearance of the screen startled him.

”Who are you?!”

”Wow, it actually connected to another world!”

The shipgirls crowded around Setsuna, openly scrutinizing the man on the screen—Muzan Kibutsuji, the Demon King of the Demon Slayer world.

”This is the Demon King you mentioned? He doesn’t look all that impressive…”

”He doesn’t seem scarier than the Siren Purifiers.”

”He’s afraid of sunlight? So, if we dropped a hydrogen bomb on him, he’d be done for, right?”

”???”

Muzan, in the Demon Slayer world, was utterly bewildered by what he was witnessing.

A group of beings from an unknown world was observing him through a holographic screen, commenting on him as if he were some kind of exhibit.

They made strange remarks like, ”He looks so weak,” and ”Can you show us one of your Blood Demon Arts?”

”Look at that Demon King—what a loser!”

”Ayanami, Ayanami, why don’t you cut him a bit with your ship-cutting sword?”

No matter what he did, Muzan’s attacks had no effect on the holographic projection. Nor did he have the ability to cross the interdimensional connection to attack Setsuna in retaliation.

All he could do was seethe impotently in his own world.

Ten minutes later.

Setsuna closed the world map. He refrained from contacting any other worlds, both to minimize interference with their timelines and for safety reasons.

After all, some beings like Spirit of Origin or Enlightened One might have the ability to traverse worlds—it was best not to provoke them unnecessarily.

The shipgirls, however, looked a bit disappointed.

”I never imagined… so many places, so many strange people and stories beyond our world…”

”I thought fighting the Sirens was the sole meaning of our existence.”

Enterprise leaned back on the sofa, staring at the ceiling.

”Hmph! One day, I must visit these other worlds and see what the British Empire looks like there!”

”What? The Sun Never Sets Empire has fallen?! What? We’re not number one anymore?!”

Queen Elizabeth adjusted the small crown on her head, so shocked she nearly fell off her chair.

”The multiverse is vast, as vast as the heavens and earth themselves. It truly makes one feel like a mere speck in an endless ocean.”

Yat Sen sighed softly, her expression pensive.

Dressed in a white cheongsam with floral embroidery, she exuded the poised elegance of a classic Eastern shipgirl, every move a display of refinement.

”Ahem.”

”Mr. Setsuna, it seems your situation is rather bleak, isn’t it?”

”Living alone on a ruined planet, struggling to survive—must be quite lonely?”

Richelieu, less interested in other worlds, kept her focus on Setsuna and his homeworld.

”It’s not so bad.”

Setsuna chuckled.

Starting with nothing didn’t bother him. At least he had shipgirls as neighbors.

The Honkai Universe might be struggling to survive, but they were putting up a fight against Honkai energy. He could even visit that pink elf lady in the future.

It was far better than having a Fallen Empire on one side and a genocidal exterminator on the other.

”Well, that’s the gist of it.”

”I think we could establish some form of cooperation, don’t you?”

Setsuna glanced at the shipgirls.

He secretly hoped they’d start calling him ”Commander” instead of the somewhat distant ”Mr. Setsuna.”

Still, status had to be earned—there was plenty of time for that.

”Yay! I think we should totally discuss cooperation!”

Before any of the flagships could speak, a small shipgirl raised her hand enthusiastically.

”There are so many other worlds! If we can’t beat the Sirens here, we could just move the entire harbor to another world!”

”We could all live on Earth in that world and never have to fight again!”

”...”

”Are you a French shipgirl? Already planning to retreat?”

Setsuna teased.

”Well, my world is quite large. If you want to move there, it’s doable…”

”G? How did you know? I’m with the second fleet of the Vichya Dominion…”

Bonk!

The small shipgirl got a flick on the forehead from Richelieu, who covered her head and crouched down in pain.

”First of all, we must persevere in our war against the Sirens.”

Richelieu cleared her throat awkwardly.

”Secondly, Mr. Setsuna, I hope you won’t hold any prejudices against the shipgirls of Iris Libre and the Vichya Dominion.”

”Let’s discuss the cooperation agreement.”

”The harbor sincerely wishes to collaborate with you and hopes to bring prosperity and development to both worlds.”

Negotiating diplomacy with the shipgirls was relatively straightforward.

For one, they were inherently kind and straightforward, without the dirty tricks and ulterior motives of typical politicians.

Secondly, their interests aligned well, and it didn’t take long to reach an agreement.

The harbor would provide personnel, while Setsuna would supply land and resources.

A vanguard fleet would be dispatched from the Azur Lane world to Earth to assist him in developing his world. In return, Setsuna granted them certain rights to extract resources like oil and minerals from Earth, which would be used to support the harbor.

Material transportation between the two worlds would occur periodically whenever the dimensional portal was opened.

Once the general framework was settled, all that remained were the finer details of the agreement—such as the number of personnel to be dispatched from the harbor or the quantity of resources extracted per operation.

Though Setsuna didn’t particularly care if the shipgirls extracted a bit more, Enterprise insisted on handling every line item with meticulous precision.

She wanted to ensure that the agreement was fair and just, not an exploitative arrangement where the harbor took advantage.

Compared to the Bald Eagle from his previous life, the shipgirls of the Eagle Union here were practically paragons of morality.

Thus, Setsuna decided to stay at the harbor for the time being, waiting for the shipgirls to finalize the agreement.

In the meantime, he took the opportunity to learn more about this world.

The next morning.

A sliver of sunlight slipped through the curtains into the guest room at the harbor.

Setsuna slowly opened his eyes.

And was immediately greeted by two… overwhelming ”forces of sin.”

Ah, no, it was Belfast.

As the head maid of the Royal Navy, Belfast had been assigned full responsibility for Setsuna’s daily care, treating him as an honored guest.

Her maid uniform was anything but modest—a daring design that walked the line between propriety and distraction. The snug fit accentuated her elegant figure, while the plunging neckline revealed the soft curve of her cleavage, her fair skin catching the light in a way that seemed almost deliberate.

It was a striking blend of professionalism and allure, the kind of attire that seemed designed to both serve and captivate.

”Mr. Setsuna, breakfast is ready,” she said, her composed tone and impeccable manners contrasting with the provocative cut of her attire.

Leaning down slightly to assist Setsuna as he rose, Belfast’s silver hair cascaded forward, a few strands falling delicately over her chest. The subtle shift in her posture momentarily deepened the view afforded by her uniform, unintentionally drawing Setsuna’s attention for a fleeting moment.

His gaze lingered just long enough for him to feel flustered before he quickly averted his eyes, unsure whether to admire her professionalism or be completely disarmed by her presence as they moved together to the washroom.

It was an entirely novel experience for him. In the twenty-something years of his life before this, Setsuna had never encountered such a dedicated—and strikingly elegant—maid.

Compared to the part-timers in low-budget cosplay maid cafés back on Earth, this was an entirely different league.

”Do you have any plans for today?”

Belfast asked softly, standing behind Setsuna as he ate.

”Not really. Enterprise, Yat Sen, and Bismarck are still hashing out the details of the agreement. I was thinking of exploring the harbor to see what life is like here.”

Setsuna replied.

He was genuinely curious about how the shipgirls lived and the extent of Azur Lane’s advanced technology.

”In that case, may I guide you on a tour?”

Belfast bowed slightly.

”Of course, I’d love that.”

After stepping out of the main building, the two walked side by side along the harbor’s paths.

Before long, Richelieu joined them, and the two-person stroll naturally became a trio.

As they walked, they noticed a number of little shipgirls sneaking behind them, peeking out from behind buildings and curiously observing Setsuna.

It felt like being watched by children marveling at an alien visitor.

”The harbor currently has over 500 shipgirls, divided among the Eagle Union, Royal Navy, Dragon Empery, Iris Libre, Northern Parliament, Sakura Empire, and several other major fleets.”

”We are born in this world, yet retain vague memories of our time in service.”

Belfast and Richelieu explained as they walked.

Each shipgirl corresponded to an actual warship from the real world. For example, the Eagle Union represented the United States, while the Royal Navy was unmistakably British. As for the Dragon Empery, shipgirls like Yat Sen, Ning Hai, and Ping Hai made their origins abundantly clear.

”You don’t have many people.”

Setsuna noted.

From the perspective of a civilization, Azur Lane’s population was pitifully small.

However, their combat effectiveness more than made up for it.

”Quantity means nothing. Advanced technology and tactics are the keys to winning wars.”

Richelieu commented flatly.

”With so few people, who handles your logistics and maintenance?”

Setsuna asked.

”Basic tasks like cleaning and transporting are handled by the Manjuus.”

Richelieu reached out and grabbed a small yellow bird, about 30 centimeters tall, from the roadside.

”Don’t be fooled by their size. They’re surprisingly strong—they can carry torpedoes and naval guns.”

”!”

The little Manjuu flapped its wings furiously in protest as it was lifted by the back of its neck. It resembled an overfed chicken, round and chubby.

”Oh, the mascots of Azur Lane. I saw them a few days ago.”

Setsuna studied the Manjuu but chose not to dwell on where it got the strength to carry heavy munitions or how the shipgirls communicated with it.

”What about construction and repairs?”

”That’s the job of the Bulins. They may not seem very bright, but they excel at maintenance and manufacturing tasks.”

They led Setsuna to a factory-like building.

On the spacious grounds, a damaged cruiser was suspended in mid-air. Its turret and port side were heavily damaged—clearly, the shipgirl’s body was undergoing repairs.

”Burin!”

”Welcome to the repair factory, burin! If you have any questions, just ask a Bulin, burin!”

A golden-haired, red-eyed shipgirl wearing a gold dress greeted him with a cheerful yet slightly foolish grin. She held two oversized drills in her hands, looking like an overzealous construction worker.

”Golden Bulin?!”

Setsuna was stunned. This was the game’s star-upgrade support unit, and now it was responsible for logistics?

Looking around, he saw numerous Purple Bulins dressed in white skirts and wielding large wrenches, diligently working.

Each Bulin had an identification badge on their chest.

”MK-0556?”

”You’re Bulin No. 556?”

Setsuna found the naming convention oddly familiar.

”Correct, burin! I’m Universal Bulin Unit 556, burin!”

The Purple Bulin jumped for joy.

”There are over 3,000 Bulins in the harbor. They manage the munitions factories and handle repairs, construction, and similar tasks.”

Richelieu explained.

Unlike shipgirls, who were based on real warships and unique, all Bulins looked identical and could only be distinguished by their serial numbers.

”The Bulins are incredibly efficient. Once, after a battle with the Sirens, I was nearly decommissioned, but they repaired me in two or three days.”

”During long-range expeditions, we sometimes bring a few Bulins with us for support.”

Belfast added.

”...”

”So they’re like construction fairies, then.”

Setsuna nodded in understanding.

It made sense for the Bulins to handle logistics since the shipgirls here didn’t need to consume them for upgrades.

Still, repairing a battleship in just two or three days was an impressive feat. Clearly, those oversized wrenches weren’t just for show.

Looking at these super-soldier workers, Setsuna felt his inner infrastructure enthusiast flare up.

”Can you build highways, high-speed rail, airports, or nuclear power plants? What about CNC machines, microcontrollers, and semiconductors?”

”Burin?”

The Bulin tilted her head in confusion.