Crossover Shipgirls: Building a Dimensional Empire from Scratch

”Mini Formidable?”

Everyone curiously examined the little Formidable.

She had exactly the same hair and eye color as Formidable—completely like a baby version of the chubby dragon.

Round and plump, she was unbearably cute.

”I am the third ship of the Illustrious-class. One day, I will grow into a great armored carrier. In order to become an outstanding lady, I humbly accept the Commander’s training…”

The little Formidable introduced herself to Setsuna with a serious face.

”Oh, Commander and I have a daughter now!”

Formidable’s maternal instincts overflowed as she lifted the little girl high.

”She’s… a bit heavy? Why does she feel heavier than Taihou-chan and the destroyer-class lolis?”

Maybe it was just her imagination, but she was convinced the little Formidable had inherited her excellent genes.

For example—weight.

Absolutely her real daughter, no doubt.

”Put me down! I want Commander to hold me!!!”

The loli flailed her arms and legs in protest from mid-air.

”Not bad at all.”

Setsuna felt that having more little shipgirls around wasn’t a bad thing at all.

They looked adorable and charming.

”Me, me, me—I’m next!”

After Little Formidable’s summoning, the other shipgirls crowded around excitedly.

Not just oathbound ones, but even many others rushed in, forming a noisy bundle.

”Akagi! You’re not even oathbound! What do you need to make a little shipgirl for?!”

”This is called ’get on the train first, buy the ticket later!’”

”Well, my lord once said he wanted a little Amagi, so this concubine is here to fulfill his wish…”

”Ah???”

”Darling, me first, me first! Since I just won the cooking match, right?!”

Soon enough—

The cat-eared maid sat next to Setsuna.

Shua—

The same procedure, extracting energy from the two of them, mixing it into a Wisdom Cube.

And another summoning.

”Darling! Rub rub sniff sniff~ Ehehe, thank you for bringing Cheshire into this world—this is my gift to you!”

A tiny cat-eared girl landed on the floor.

She wore the exact same maid outfit and white stockings as the older Cheshire, but was barely half her height.

The oversized bow at her back nearly dragged on the ground.

Little Cheshire was just as cute as Little Formidable. She leapt into Setsuna’s arms, rubbing her head against him again and again.

Hiss—

Setsuna suffered another loli critical hit.

”Next, next—you all have so many people, hurry up.”

Purifier urged the shipgirls waiting in line.

”Seriously, who queues up to have children with the Commander?!”

Shua— Shua—

White light flashed again and again.

One little shipgirl after another was summoned.

”Greetings, Commander! I am Royal Navy’s Illustrious-class carrier, Illustrious! Let us spread the light of love and peace across this world together!”

”I am the battlecruiser Amagi of the Sakura Empire. Here in this port, I’ll grow healthy and strong to protect Commander and Akagi with all my might—by eating well and sleeping well, of course!”

”…Mhm, I am Shinano. The rest doesn’t matter much. The future is unpredictable, after all. For now, I just want to sleep here peacefully…”

”...”

Some were Setsuna’s oathbound shipgirls. Others were ones he had specifically wanted summoned as little versions.

The older shipgirls had no objections. With the Siren girls’ help, in less than two hours—

The Siren port was filled with over a dozen loli shipgirls.

Little Illustrious, Little Shinano, Little Amagi, Little Belfast…

Big shipgirls held hands with little ones, a harmonious and heartwarming sight.

”Phew, that’s enough for today. I’m a bit tired.”

After completing the final infusion, the Compiler spoke softly.

”Mhm, thanks.”

”We’ll grab some specialty goods from the port to thank you later!”

The shipgirls warmly expressed their gratitude to the Siren girls.

The entire naval port became lively, full of the cheerful chatter of little shipgirls everywhere.

”Commander, Commander, now it feels like we have daughters too~”

Formidable held Little Formidable, while Belfast cradled Little Belfast at her side.

”...”

Setsuna didn’t really understand their strange mindset, but the little shipgirls were undeniably adorable. Having more of them around certainly wasn’t a bad thing.

Especially Little Amagi and Little Belfast—they were so cute it was almost painful.

”Alright then. From now on, you’ll attend classes with TB and Taihou-chan. I’ll take you to get familiar with the capital.”

Setsuna gave the order.

The little shipgirls had inherited some of the knowledge and memories from both him and their original shipgirl counterparts. They recognized him as Commander, making education much easier.

”Okay, Commander~!”

A group of little lolis surrounded him as they left the Siren naval port.

Under the guidance of the big shipgirls and the Commander, they began to explore and understand the place they would now live in.

...

”Whew—”

After sending off Setsuna and the noisy shipgirls—

Observer and Purifier both let out a long sigh of relief.

”Finally done. Honestly, Commander… making me do this kind of thing…”

Observer muttered, still remembering the warm feeling from being patted on the head earlier.

”Forget it, forget it. Just think of it as helping them out.”

Purifier shook her head, opening up a holographic interface to begin uploading data.

”Eh, I don’t even know if the mainframe can receive this data. Whatever, duty is duty…”

As members of the Siren Experimentals, their job was to observe and experiment.

They were required to periodically record their work results into the Siren database and mainframe.

At first, the Siren girls had taken it seriously.

Every month or two, they would write up comprehensive and detailed reports.

For example: discovering an otherworldly Commander, arriving in a new world, refitting shipgirls into space warships, and so on…

But since the Arbiters had long been out of contact, Purifier wasn’t even sure if they could see the messages she uploaded.

Over time, the whole process became little more than a ritual. She had no hope that it would actually reestablish contact.

”They probably can’t see it. Otherwise, they would’ve contacted us already.”

”Yeah… hopefully the Commander unlocks inter-world travel tech or skills soon…”

Purifier shrugged, scribbling casually in the routine report.

[Transmitting data… Transmission complete… No response from recipient.]

The screen displayed the predictable line of text.

”Click—whatever, let’s go eat.”

The two Siren girls dove into the sea, heading toward the capital.

...

Azur Lane World.

A certain chaotic parallel universe.

This dimension was completely separate from the harbor world.

The planet held only pure chaos and void. Energy diffused wildly through the atmosphere. Countless Siren fleets floated across the seas.

Compared to the Sirens the shipgirls had once fought, these were larger, more advanced, more aggressive in design.

Most of the humanoid Sirens here wore dark cyan-black colors, completely different from the black-and-red aesthetic of the Experimentals.

In the deep sea, a massive fortress-like base loomed.

Its exterior was built from black, blue, and red metals, solemn and imposing.

Humanoid Sirens patrolled everywhere.

Inside—

A pale-skinned, white-haired, red-eyed Siren girl with shark-like rigging stood before a bizarre device, scanning the holoscreen in front of her.

She was the Siren Arbiter: Empress.

Unlike the research-focused Observers and Purifiers, her faction belonged to the violent arm of the Sirens—the Arbiters.

They possessed the strongest military power and highest technological strength of the entire legion. Unfortunately, due to an accident, they had lost contact with the Experimentals.

[Mainframe Repair Progress: 32.3%... 32.5%...]

[Dimensional Space Confirmation… Unable to Locate.]

”Still no good?”

Empress frowned, scanning the endless streams of data.

As part of the Arbiters, they too worried about where the Experimentals had ended up.

But they had been unable to reestablish contact.

”Let’s wait a little longer. Dreamweaver is still deconstructing this universe. Before long, we should be able to break free and return to our original world.”

”Maybe we’ll find them there.”

Another Arbiter, silver-haired with blue eyes, spoke calmly.

”That works.”

Empress nodded, deciding to patiently wait until they could escape this parallel universe.

Suddenly—

Beep—

A message came through the mainframe, the identifier clearly showing its origin.

The Experimentals.

They were submitting one of their periodic work reports.

”!!!”

Both Arbiters froze, then hurriedly leaned in.

”They’ve restored connection to the mainframe?!”

”No… no, it’s one-way transmission. Probably due to some energy fluctuations, their messages occasionally slipped through.”

With excitement, Empress opened the report.

”Let’s see… During their time lost in another universe, what has the Experimentals been doing?”

”They’re the pride of the Sirens, pioneers of frontier technology. They should be continuing our experimental plans—or maybe developing new projects?”

”After losing contact with us, they must have been so worried… I wonder how their relationship with the shipgirls has gone…”

With all sorts of thoughts swirling, the two Sirens carefully read the fragmented report.

Some of the data was missing due to interference, but enough was intact to reveal quite a bit.

The message was written by Purifier, bearing her signature.

The first part was fairly serious. But later on—likely after long disconnection—Purifier had clearly started going off the rails.

”22XX/XX/XX: Arrived at the Starsea Empire. I will continue fulfilling the duties of the Siren Experimentals.”

”XX/XX: Within the Starsea Empire, helped the Commander and Taihou create a little shipgirl, named Taihou-chan. Very cute~”

”XX/XX: Helped the Commander design a super-invincible starship. Probably one shot could blow up the entire Arbiters. We’re awesome.”

”XX/XX: Helped the Commander and Formidable give birth to a Little Formidable. Weight XXX, height XXX. Mother and daughter safe.”

”XX/XX: Helped Illustrious create a Little Illustrious. P.S.: Next time let’s try making a little Siren with the Commander…”

”...”

”???”

The two Arbiters’ expressions shifted from joy, to confusion, to utter disbelief.

They glanced at each other, both with giant question marks over their heads.

”What the hell is the Experimentals doing?”

”...”

...

Inside the metallic fortress—

The Siren Arbiters gathered together, seated around a round table.

By all logic, reestablishing contact with the Experimentals should have been a joyous event—finally, they had located their colleagues lost in a parallel universe.

But after reading the data on the holoscreen, every Arbiter wore a baffled expression.

”Can… someone explain this to me?”

The Arbiter who resembled the Compiler—white-haired, blue-eyed, with jellyfish-like rigging—spoke first.

”During their time stranded in another dimension, just what did the Experimentals do?”

”They’ve formed a cooperative relationship with the shipgirls? Well… that part isn’t too strange. But what exactly is this ’Starsea Empire’?”

”And what the hell does ’mother and daughter safe’ mean?!”

The Arbiters stared at the endless reports of little shipgirls being born, completely dumbfounded.

After a few years apart, had the Experimentals become so incredible they were now helping shipgirls give birth?!

Was this really the kind of work Sirens were supposed to be doing?!

Weren’t they supposed to be researching advanced weaponry?

No, at a fundamental level, this shouldn’t even be possible.

Temparance shook her head, unable to comprehend it.

Shipgirls were incarnations of warships. How could they possibly have children?

”Let’s assume the Experimentals achieved some breakthrough in Wisdom Cube research…”

Empress thought for a moment, choosing to defend her old colleagues.

”And then they used this breakthrough to help shipgirls give birth to little shipgirls?!”

The other Arbiters still couldn’t wrap their heads around it.

”And it seems they’re working for someone called the Commander?”

Another Arbiter, silver-haired and blue-eyed, with attire decorated by sea butterflies, asked curiously.

From the fragmented reports sent by Purifier and Observer, much of the data had been lost in transmission. But piecing together the fragments revealed some details.

The entire Experimentals had joined the Starsea Empire, obeying the Commander’s orders.

And they had even used Siren technology to help him.

From the tone of the reports, the Experimentals seemed quite satisfied with their new life.

Purifier had even written in one report: ”We helped the Commander build a super-invincible starship. It could probably blow up the entire Arbiters with a single shot. We’re awesome.”

”…Unbelievable.”

The Arbiters grew more and more perplexed as they read.

”In that experimental universe, aside from shipgirls, there shouldn’t have been any other beings. So where did this new civilization come from?”

”And judging from the scraps of info, their technology level is very high—they’ve already reached the space age?…”

Because the most critical information—Setsuna piercing through worlds and arriving at the port—hadn’t been transmitted, the Experimentals’s report became a riddle for the Arbiters.

”I’m more curious about the starship they built…”

Lavos mused.

”One shot to wipe out the entire Arbiters? Fine, I get that Purifier and Observer are proud of their achievements, but… are they trying to rebel?!”

”...”

”Forget it. At least we know they’re alive and well.”

The Arbiters discussed a little more, but couldn’t glean further answers from the limited data.

”Find a way to contact the Experimentals.”

”We need to locate them, and confirm exactly what they’re doing.”

...

”Darling! Rub rub sniff sniff~ Ehehe.”

At the administrative center, during his free time, the place now resembled a kindergarten—little shipgirls running everywhere.

Little Cheshire rubbed herself all over Setsuna.

Little Enterprise sat with the older Enterprise, earnestly reading books.

Her dream was to become the Eagle Union’s strongest warrior. But since she had only just been summoned, she was still essentially an ordinary sea vessel.

She needed to study starship knowledge before undergoing refit.

Little Belfast followed the Head Maid, learning the etiquette of the Royal Maids.

This tiny maid was even shorter than a destroyer. When serving tea to everyone, she had to stand on tiptoe, raising both hands just to barely place the tray on the table.

”Heave… ho!”

”Commander, your tea and snacks.”

Little Belfast mimicked the Royal Maids, giving a proper curtsey.

”Thank you, go rest now.”

Setsuna patted Little Belfast’s head and handed her a candy.

The little shipgirl ran off happily.

Elsewhere, Little Amagi, Little Formidable, and Little Shinano were each with their elder counterparts—some reading, some napping.

Everything was harmonious.

”Lolicon. Absolutely hopeless.”

Gudako squinted at the noisy room full of little lolis.

”Commander, I leave with Hua for a few days to practice Taixuan Eminence, and you secretly make a whole bunch of little lolis?!”

”This is open and aboveboard.”

Setsuna flicked Gudako on the head.

”Besides, what business is it of yours if I have little shipgirls with my wives?!”

”…Then how about I give you a child too?”

Human Evil’s eyes sparkled, eager to try.

”No thanks. Little shipgirls won’t ever grow into troublesome brats. I like eternal little lolis with unlimited shelf life.”

Setsuna rejected her with a straight face.

”???”

”You—your tastes are seriously twisted, aren’t they?!”

Gudako’s lips twitched.

”So jealous…”

Kanae touched her own belly.

Unfortunately, the Commander only seemed interested in little shipgirls for now, with no other plans.

Just as Setsuna was playing with the little ones—

”Commander!!! Emergency!!!”

Purifier’s voice came from outside.

The Siren girl tumbled into the administrative center, breathless, rushing straight to Setsuna.

”The Arbiters just sent me a message!!!”

”Huh?”

Setsuna blinked in surprise.

The Siren Arbiters had been completely out of contact ever since he’d lured Purifier and the others away. According to the Compiler, they’d been lost in some parallel universe within the Azur Lane world.

They could only be retrieved once he developed inter-universe travel technology.

”Where are they?”

”No idea.”

Purifier opened a holoscreen, showing the message from the Arbiters.

It was short, written in a peculiar Siren language.

”They really were thrown into a strange parallel universe of Azur Lane. They’re currently trying to escape.”

”After accidentally receiving the last message I transmitted to the mainframe, the Arbiters responded.”

”They want us to provide coordinates to lock onto this universe.”

Apparently, this transmission method consumed enormous amounts of energy and resources. The Arbiters hadn’t revealed much else—only that the Experimentals needed to build a beacon to give them a target. Then they would come on their own.

”So… they’re asking for a beacon. Are these Arbiters planning to come here for a fight?”

”You’re not going to be their guide, are you?!”

Richelieu gave Purifier a sharp look of suspicion.

”No way! We’re on the Commander’s side!!”

Purifier shouted her innocence.

”And besides, the Arbiters can’t beat the Commander anymore! The Eternal Snowfall alone could probably scare them to death…”

”Ahem, so if that’s the case, doesn’t that make the Experimentals the strongest Siren department now? Hmm, I’ll need to file a request with Dreamweaver…”

”...”

Setsuna thought for a moment.

A few years ago, encountering the Arbiters would have been a nightmare.

But now… after spending time with the Siren girls, he realized his old stereotypes came entirely from the mindless, mass-produced Sirens with no consciousness.

The higher Sirens were all individuals, with their own wills.

Shipgirls I want. Siren girls I want too~

”Alright. Build the beacon. Bring them back.”

—

—

40 Advanced Chapters Available on Patreon:

Patreon.com/DaoOfHeaven