Crossover Shipgirls: Building a Dimensional Empire from Scratch

The sudden discovery of five new neighbors sent a wave of excitement through the base.

Everyone began pouring over the data and eagerly signing up for the Commander’s interdimensional expedition team.

Generally speaking, magic-side companions like Spirits and Heroic Spirits preferred visiting magic worlds.

They were all clamoring to meet the Goddess of Wisdom, Aqua, and brainstorm ways to help Madoka.

The shipgirls had their attention locked on the Kantai Collection world.

Azur Lane shipgirls wanted to spar with the KanColle girls, while the Siren girls were itching to take on the Abyssals.

Setsuna felt they were all just looking for a chance to bully someone. They’re all my wives—stop fighting each other.

As for normal folks like Shinobu and Kanae, they were just hoping more Uma Musume would come to the base.

Hanging out with high-tier elites all the time was stressful. Some cute, relaxing horse girls would be a nice change of pace.

However, interdimensional operations would have to wait until the Commander and the other shipgirls finished their hull upgrades.

Over at the Starbase shipyard,

In the massive assembly plant stretching hundreds of kilometers, countless starships floated in place.

Carriers, battleships, cruisers, and destroyers were suspended in layers across the orbital docks by classification.

An uncountable number of Bulins and Angeloids were working non-stop—dismantling hulls, refitting weapons, installing FTL engines...

Only now did many shipgirls, used to living on Earth, begin to realize the true significance of the Starbase to an interstellar civilization.

In space, everything is three-dimensional.

The naval base outside the capital could only handle upgrades for around ten small ships at a time. For battleships or carriers, it could only squeeze in two or three.

The Eternal Snowfall alone would completely occupy the dock when undergoing refits.

And considering that starships would only grow larger, eventually the facilities would no longer suffice.

But in space, building space is virtually unlimited.

Construction can extend outward from a central point in all directions.

The starship assembly yard within the titan fortress was like a colossal matrix—so vast its length, width, and height couldn’t be seen in full.

In the zero-gravity, open vacuum environment, nearly half a fleet’s worth of shipgirls were undergoing refits at once.

As long as there were enough Bulins and resources, theoretically hundreds of starships could be assembled simultaneously.

An incredibly terrifying burst capacity.

”The Commander said he wants more weapons installed this time. Make the keel and frame larger.”

In the shipyard, the science loli held a structural blueprint, directing the Specialized Bulins in their work.

”Yes, yes, extend the keel. Length... just eyeball it. We’re in the space era now—use your imagination!!!”

”Besides, the Commander doesn’t need to worry about portability. He can shrink and expand at will. Not to mention there’s still the Gundam form...”

”As for weapons... we recently developed a few new gadgets. Should we give them a try?!”

Seizing the refit opportunity, Kayo Senju, the science lolis, and the Bulins went wild on the Eternal Snowfall’s hull—modifying and testing like mad.

Weapons for an FTL starship were researched entirely from scratch by the lolis, with zero reference points. Setsuna had only offered a few vague directions based on his Paradox Interactive war criminal instincts.

Whether they’d work well, how powerful they were, or whether they were suited for large or small ships—no one had a clue.

They could only install them on the starships and test them one by one.

”Gamma laser! Experimental gamma laser—mount it!!”

The Specialized Bulins clambered over a turret and welded on a strangely shaped weapon.

Fwoosh—

A blinding red laser streaked across space, striking a test target in Mercury’s orbit and leaving a small dent.

”Uh, why is this weaker than a hydrogen bomb? Did we miscalculate the output?”

The loli analyzing the data scratched her head.

”Next—Skycloud Lightning.”

The rainbow Bulins went to work.

Zzzlaa —

From the starship’s turret, arcs of high-energy lightning fired off, looking incredibly cool—like the universe itself was thundering.

”Skycloud Lightning can pierce shields and hull structures, but the damage and trajectory are unstable. After firing, the impact pattern becomes a chaotic model—completely unanalysable.”

The science loli scanned the data and scratched her head again.

”Next up—experimental photon spear. Uh, is this what the Commander called a ’light lance’?”

...

Meanwhile, in the Starbase’s main control room.

The science lolis and Aurora were carefully reviewing and analyzing the exploration reports from the research probes.

After completing the FTL engine, the Starbase had produced dozens of unmanned research ships to begin deep-space exploration.

They set their engines to maximum and headed toward the most life-likely star systems marked on the star map.

Quite a few systems similar to the Solar System were discovered.

Planets with atmospheres, water cycles, and even ones with ideal climates and air quality for colonization were encountered.

But all around them—it was dead silent. Nothing.

The ships had ventured thousands of light-years out, and still found no trace of alien civilizations.

No ruins, no ships, not even signals.

”Strange... if alien civilizations really existed, their ships or communication systems should at least be leaking some form of data...”

In the control room, Aurora and the science lolis looked puzzled.

A powerful spacefaring civilization couldn’t possibly hide all traces of its presence.

It would’ve surely left behind traces of megastructures within its star system:

Things like stellar rings, small mining stations, synchronized satellites...

Even if the civilization was extinct, there should at least be debris.

But so far, not even space junk had been spotted—let alone alien tech.

The most complex lifeform they’d found was primitive single-cell organisms.

”So it seems... we’re literally alone in the galaxy, huh?”

They flipped through page after page of research reports.

Tens of thousands of documents and analysis results had been relayed to the Starbase control center—this served as the command hub for all unmanned probes.

”Ugh...”

”We used to fear that when we first entered space, we’d find ourselves surrounded by advanced super-civilizations...”

”But now it seems like the opposite? Are we really the first intelligent civilization in this galaxy?”

One of the loli scientists swayed her head and said,

”My worst-case prediction was that after developing FTL, we’d run smack into a Fallen Empire.”

”The best case would be finding primitive, pre-space civilizations we could study sociologically and biologically.”

”But now what is this?! We’ve scanned thousands of light-years, and the only ’life’ we’ve found is some alien bacteria?!”

Hearing that, the lolis seemed a little deflated.

They both wanted to encounter aliens, and yet feared they’d be too powerful to handle. A deeply conflicted mindset.

”Speaking of which... the Commander’s never said which universe this is...”

Aurora gazed at the stars outside the window, lost in thought.

She came from the Azur Lane universe, the lolis from the Black Bullet universe, the dragon girls from the Dragon Maid universe, the Spirits from the Date A Live universe...

But the Commander’s world—was a complete mystery.

No one knew where this place really was.

Suddenly—

Beep —

Beep beep —

An AI alert sounded.

Amid the sea of reports, the AI flagged an anomaly.

”Alert: Anomaly detected!!”

”Alert: Anomaly detected in the Kepler-160 star system—non-natural structure discovered.”

”Confirmed. Object is not naturally occurring—suspected alien construct.”

”!!!”

Aurora and the science lolis immediately dropped what they were doing and accessed the front-line research report.

It was a star system approximately 3,000 light-years from the Solar System.

Due to the distance, it would take time for a probe to arrive, but the observed target was massive—prominent even on an astronomical scale.

The detectors had managed to capture some blurry images.

The astronomy loli zoomed in, and in, and in—

”This is...”

Everyone in the control room was dumbfounded.

It was a celestial body larger than a planet, with a strange appearance.

It looked like a miniature black hole, surrounded by a luminous accretion disk emitting a ghostly green glow.

Above and below the celestial body, mechanical claw-like structures floated—just one glance made it clear this was an alien artifact.

The mechanical claws functioned like stabilizers, maintaining the object’s position in space.

Amid the vast, desolate cosmos, the object and its flanking constructs stood out dramatically.

”What is this?”

Question marks practically popped out over Aurora and the lolis’ heads.

The knowledgeable Kayo Senju rifled through the tech concepts Setsuna had explained in the past.

The Commander didn’t personally manage the R&D projects, but he often talked about strange sci-fi technologies—things like warp drives, colossi, hyperspace...

Some of the lolis found them feasible and tried to reproduce them; others just listened for fun.

Kayo searched for a while, then pressed her forehead, deep in thought.

Matching it up against her memories—

”This is... an L-Gate?!”

...

...

”That’s an L-Gate.”

”I suspect... my wife is inside.”

When Setsuna received the report from Aurora and the science lolis, he slammed the table and stood up.

Too damn familiar.

Every veteran Paradox war criminal and Stellaris player knows exactly what this is.

And he now knew which universe he’d been dumped into.

”What? L-Gate? There’s someone in there?!”

The shipgirls and lolis looked confused.

”Yes. The L-Gate is an ancient construct built by a lost civilization. It leads to a star cluster completely disconnected and far away from the Milky Way.”

”It could house a miraculous nanite empire—or beautiful nanomachine girls, your designated fourth-wall-breaking wife.”

Setsuna calmed himself.

He gave everyone a simplified explanation of the L-Gate.

It was a relic of a long-dead, ancient civilization—a sealed gateway.

On the other side was a distant star cluster, far from the Milky Way.

As for what lay within—that was completely random.

If lucky, you might meet a nanomachine girl who pledges loyalty and says she’s waited 5,000 years for you.

You could also encounter a mysterious star empire or a neutral nanite dragon.

In the worst-case scenario? A hostile Grey Goo fleet.

”Wait, an ancient civilization built it? That means there are—or were—other advanced civilizations in this universe?!”

”Also... why are you so familiar with it, Commander?”

Kayo Senju immediately picked up on the deeper implications.

That gate clearly wasn’t a natural phenomenon. Its creators must have been extremely advanced.

”Because this is the Stellaris universe.”

Setsuna answered plainly.

The discovery by the research probe solved a question that had been bothering him for ages:

—Which dimension did I get sent to?

He’d been pondering this since starting out naked in a random system.

The system never answered, never offered any hint as to where he actually was.

Only the Stellaris-style star map and UI gave him vague suspicions.

Now, upon seeing the L-Gate—everything was confirmed.

There’s only one universe with L-Gates:

The homeland of Paradox war criminals—the Stellaris world.

Fitting, in a way.

”Wha?!”

The shipgirls and lolis gasped.

”Commander, so this is that love-and-peace world you mentioned? The one full of colossi, where aliens get turned into jars and biopower batteries?!”

”With terrifying Fallen Empires, genocidal exterminators, killer swarms, and racially pure lunatics?!”

”And possibly those Crisis nutcases trying to blow up the entire galaxy?!”

”Should we just go back to the Azur Lane universe instead?!”

The control room instantly erupted into chaos.

Now that they knew their universe was crawling with freaks and nightmares, no one could stay calm.

It felt like they’d just stepped out of the tutorial village and stumbled into an S-tier raid boss zone.

”That said... things here seem a bit off from the Stellaris I remember.”

Setsuna stared at the star map, deep in thought.

The Stellaris universe was supposed to be overflowing with civilizations.

Starfleets, pirates, traders, roaming juggernauts, space whales...

Everywhere you looked, someone was zooming around.

Comms and trade networks were booming and widespread—it was supposed to be lively.

But here? They’d traveled over a thousand light-years and hadn’t seen even a single alien.

They hadn’t even run into an amoeba.

”Single-player mode?”

Setsuna’s expression turned a little strange.

”Maybe... we really did spawn in some remote galactic countryside?”

Gudako offered another bold theory.

”Tsk tsk tsk, maybe the Milky Way is a little too urbanized.”

”...”

”Very strange.”

Setsuna rubbed his temples. Discovering the L-Gate was irrefutable proof that this was the Stellaris universe.

But not finding a single alien in Stellaris? Was that even reasonable?!

Not even a trace—no signs of alien presence whatsoever.

He’d lived on Earth for so many years, and never once had there been sightings of alien ships flying past Earth or the Solar System.

After thinking for a bit, he looked toward Tohru and Elma.

”Have either of you sensed the presence of gods or anything like that? Like the Shroud, maybe?”

”No, Commander. Your world contains no divine or supernatural entities.”

The two dragon girls and Mio all shook their heads.

If anything supernatural existed here, their senses would’ve picked up on it instantly.

Since arriving on Earth, Tohru was absolutely certain: this was a godless world.

Otherwise, Elma wouldn’t have suggested summoning a god.

”No aliens, no Shroud either? Tch.”

Setsuna clicked his tongue.

If there were no aliens, he could at least rationalize it with probabilities—like Earth being too remote or something.

But the Shroud? That made no sense at all.

The Shroud was a hallmark of the Stellaris universe—home to four shady beings that mirrored the Chaos Gods from the Warp, and of course, the one who offers magical girl contracts and fifty years of happiness.

Now, all of that was absent. Even the psionic ascension path might be locked.

It felt like this world was missing too many key elements.

”Whatever.”

After mulling it over for a while, he decided to stop overthinking.

There was no point trying to solve cosmic mysteries with no evidence.

...

If Grey is here, that’s enough.

He turned his focus back to the L-Gate.

”Let’s deal with this first. Send a science ship to investigate the L-Gate—see if we can unlock it.”

”Dispatch a few Starship Bulins to analyze the L-Gate’s structure.”

Setsuna marked the L-Gate’s location on the star map.

”Of course, our fleet should also be prepped. Start pre-positioning at the L-Gate entrance and be ready for any unexpected scenarios.”

”...”

The shipgirls didn’t quite understand why the Commander was so obsessed with the L-Gate.

”Commander, based on what you’ve said—once we open the L-Gate, what’s inside is unpredictable.”

Richelieu rubbed her forehead.

”It could be nanomachine girls, a Grey Goo fleet, a nanite empire, or even a nanite dragon, right?”

”Correct. Technically, they’re all different forms of the Grey Tempest.”

Setsuna answered calmly.

”If we encounter friendly nanobot girls, that’s great. But what if it’s a hostile Grey Goo fleet or an aggressive nanite empire?”

Yat Sen asked, slightly worried.

”Then we seal the gate.”

Setsuna had full confidence in his fleet’s overall power.

Even if a Grey Goo fleet appeared, he could call in Lucoa, Tohru, and Elma to deal with it.

Then he added:

”I believe in my bond with Grey.”

”She’s my wife who waited tens of millions of years for me among the stars!!!”

...

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