Crossover Shipgirls: Building a Dimensional Empire from Scratch

OOOOH—

Outside Earth’s orbit, aboard the Eternal Snowfall, the wide command bridge erupted in cheers.

A planet-class starship—its sheer size was astonishing.

Even if several naval bases, three world shipgirls, and all the Spirits, Heroic Spirits, and research lolis were brought here, the place would still feel spacious.

The living area was equivalent to a large city.

Banquet halls, residential zones, even hot springs and a cinema—everything was fully equipped.

The Eternal Snowfall itself was a mobile combat platform. Its internal design concept had already far surpassed the category of a mere starship.

With the help of the holographic dome device, even while inside the ship, one could look up and see the starry sky above.

It never gave the sense of being confined in a room or cabin.

”Ahem, this time the temporal distortion ratio is 120 times. I hope you all enjoy your time on the Eternal Snowfall.”

Setsuna cleared his throat.

”Yay!”

The little shipgirls below erupted into cheers.

With a 120x temporal distortion, one night of eight hours equated to 40 days in the outside world.

After merging with the Allspark, Setsuna had grown increasingly proficient at manipulating his own temporal distortion.

Combined with the wondrous state of man-ship unison, sooner or later he would be able to make a single night last one or two years.

This had also become a standing project after every expedition.

In the past, only the harem group members were invited. After the Eternal Snowfall became a Juggernaut, it turned into a grand celebration for all.

The planet-class starship was vast enough to meet nearly every entertainment need.

Destroyer shipgirls eagerly rushed toward the cinema and hot springs.

The research lolis, too, finally had a rare chance for vacation.

Kayo Senju originally thought of using the temporal distortion time to study more of the Three-Body world’s gains, such as pondering over mathematical laws.

But the other research lolis looked at her with puppy eyes:

”Chief, Commander said we’re on holiday. Let’s rest a few days.”

”…”

The blonde loli sighed and thought for a moment.

Spending more than a month here only amounted to a single night outside. It wouldn’t delay research.

”Alright then, everyone, free activity.”

”We’ll work again after returning to the starbase.”

”Yay!!!”

In an instant, the little lolis and little shipgirls mingled together, the residential areas full of darting cuties.

Meanwhile, above the command bridge was the adults’ domain.

Beyond a long corridor lay the vast captain’s residence.

Modeled after Earth’s villas, it sprawled over ten thousand square meters.

Shipgirls, dragon girls, Spirits and more gathered there to enjoy long-awaited private time with their Commander.

Indomitable was dumbfounded as she was brought before Setsuna by Formidable, Illustrious, and Victorious.

”Commander, this is our lazy little sister~.”

”Tsk, she’s always sleeping in the port. This time she actually volunteered to come—”

Formidable patted Indomitable’s back, emphasizing the word ”volunteered.”

Then she promptly sat herself down in Setsuna’s lap.

”Oh?”

Setsuna looked with mild surprise at the voluptuous, beautiful shipgirl.

She had long black hair, and her brown-green eyes carried a trace of laziness.

Indomitable, the fourth Illustrious-class carrier—sister to Illustrious, Victorious, and Formidable. A practitioner of minimalism, she usually lazed about idly in the port.

Unless her name was called on an expedition, she could hole up indoors indefinitely.

Her figure inherited the Illustrious-class armored carriers’ trademark proportions—astonishingly large.

Of course, what drew the most attention was her peculiar maid outfit.

Her upper half could hardly be called ”clothing,” more like Sirius’s skimpy ready-to-drink attire, covering only a few critical spots with scraps of fabric.

Her lower half was clad in a black maid skirt and white pantyhose—a common style among Royal maids.

Yet no matter how Setsuna looked, it always seemed like key areas were missing some fabric.

Such was the usual Azur Lane fashion, indeed.

”Don’t you think your maid outfit is a bit improper?”

Chen Hai blinked, glancing toward Belfast.

At most, Royal maids wore low-cut outfits. The bolder ones might open a few windows here or there.

Indomitable seemed to be heading in a strange direction.

”Mm, ah, Formidable said Commander really likes Royal Maids, so I tried out this maid outfit out of curiosity…”

”But, it seems like the size is a bit off…”

Indomitable looked rather puzzled.

”It’s fine, it looks good.”

Setsuna gestured for her to sit beside him.

Sister ships should sit neatly together—the four Illustrious-class sisters, not a single one missing.

”Ah…”

As she felt Setsuna’s arm wrap around her waist, Indomitable’s cheeks flushed.

”Commander, ah…”

”Indomitable, you can’t be so shy~”

Formidable scolded her lazy sister in the tone of an elder.

”If you don’t take some initiative, the Commander will be snatched away.”

”Do you know how many of our sisters are waiting for this chance?”

In the port now, it wasn’t the Commander pursuing shipgirls—it was the shipgirls pursuing the Commander.

”Eh…”

Indomitable drew out her voice, as if to show she understood, but also as though it was a bother.

She glanced at the Royal Maid team.

”Commander, having so many maids to serve you, you must be living so comfortably… I’m so envious…”

”Then why not join them? Let Belfast train you?”

Setsuna smiled as he asked.

”No, maid work is too troublesome… I can’t do anything.”

”Then how about a tour of the Eternal Snowfall?”

Setsuna asked.

”You haven’t really been aboard much, have you?”

”Mmm…”

Indomitable dragged out her voice again.

”Better not. Just changing into this outfit and walking in front of the Commander already used up all my energy.”

”Ahh, just thinking about walking all the way here from the Akame ga Kill world today already makes me feel exhausted… yawn…”

As she spoke, she even yawned.

”???”

Setsuna was stunned. His understanding of this lazy Illustrious-class sister deepened.

”Commander, massage me, my arms are so sore.”

”Mm, if I could just nap here, it’d be even better.”

Indomitable simply flopped onto the sofa, an expression that said: I’m lying down, Commander, do as you like.

”Hey?”

”That’s going too far?!”

Formidable was half angry, half amused.

She had worked hard to drag Indomitable here so she could deepen her relationship with the Commander, yet her initiative was practically zero.

”Forget it, I’ll do it.”

Setsuna chuckled and signaled the Illustrious sisters to step outside, leaving him alone with Indomitable.

”A massage, huh…”

”Belfast and Sirius massaged me before. I barely learned a thing or two, not very skilled, so don’t mind it.”

Setsuna sat on Indomitable’s legs, brushed her waterfall-like black hair to one side, and began massaging her shoulders in the maid captain’s style.

Carrier shipgirls had excellent figures, with just the right amount of softness. Her fair, delicate skin was pleasing to the eye.

”Mm…”

”Commander, you’re actually pretty good at this.”

Indomitable was surprised, but didn’t resist.

Soon, her eyes narrowed in comfort.

Zzz…

Zzz… Zzz…

As he massaged, Indomitable drowsily opened her eyes.

”Um, Commander, isn’t your massage range a little too big?”

”Mm… if you don’t want it, I’ll stop.”

Setsuna thought to himself that indeed, among the Illustrious-class armored carriers, she was the largest, and the feel was quite good.

”You’re bad…”

Indomitable pouted, then turned her head away.

Burying her face in the pillow, she muttered softly:

”Commander, you can do whatever you want…”

”Mm, I’m not as gentle as Illustrious, nor as lively as Formidable, so I’m probably not very likable. So, if you want to take advantage of me, just go ahead… mm…”

”Just don’t disturb my sleep, and don’t go too far…”

”?”

”As expected of you.”

Setsuna was amused by her utterly lazy honesty.

But since the shipgirl herself had said so, there was no reason to hold back.

”Indomitable, you know, laziness is an illness—it needs treatment.”

He continued massaging her shoulders as he spoke.

”Oh~”

Indomitable drowsily responded.

”Commander, what do you think should be done? Actually, just letting me sleep would be enough… Zzz…”

”No, your condition is rather severe. You need an IV.”

”Eh?”

...

The Eternal Snowfall quietly hovered outside Earth’s orbit.

From Constantinople’s perspective, only a dozen minutes had passed since the shipgirls boarded the Eternal Snowfall.

But aboard the starship, a full day had already gone by.

”Commander, today it’s our turn to be with you~”

”Yesterday we let Indomitable have you, don’t you forget about us~”

Formidable pushed open the bedroom door at the top of the command bridge.

In the dimly lit room, two figures lay sleeping in each other’s arms.

Indomitable’s long black hair was spread messily across the bed as she slept soundly.

”Oh?”

Formidable revealed an as expected expression.

She chuckled softly, drew open the curtains, and activated the holographic dome.

The dazzling starlight outside projected into the room.

”Wake up!!!”

”Mmm…”

Indomitable drowsily opened her eyes and sat up.

She shook her head and gathered up her waterfall-like hair.

Looking down at the half-fallen white stockings clinging to her legs, she paused, then gently pulled them back up with her fair fingers.

After slipping back into her barely-there maid outfit, she let out a long sigh.

The moment she got out of bed, her legs gave way, nearly stumbling into Formidable’s arms.

”Hey? Are you alright?!”

Formidable was startled and helped her onto the nearby sofa.

”So tired… so exhausted…”

Indomitable’s face was one of utter despair.

”Commander is a liar.”

”?”

Formidable tilted her head. It was her first time seeing a shipgirl complain about Setsuna like this.

”Commander said I was too lazy, that I needed IV treatment, and even oral meds…”

”Liar. After the treatment I just felt even more tired. He even said I needed several courses…”

”???”

Formidable yanked the amused Setsuna off the bed and jabbed an elbow into him.

”Really? You bully my sister like this?”

”?”

”Didn’t you also learn quickly without being taught? What’s the problem?”

Setsuna asked curiously.

”I-I-I… I was just afraid of embarrassing myself, so I asked Taihou for tips in advance!”

Formidable’s face flushed red as she tried to explain.

Then suddenly realizing what she said, she pinched Setsuna hard.

”Why did I tell you that ahhhh—!!!”

”…”

”Then go back and rest.”

Setsuna looked at Indomitable.

”If you don’t want to, in the future I can just find Illustrious, Victorious, or Formidable. I won’t disturb your lazing around.”

”…”

Indomitable thought for a few seconds, visibly conflicted.

”No, I want to.”

”But having to come to you every time is troublesome. Could you come to my dorm instead?”

She seriously proposed to Setsuna:

”Mm… I’m home most of the time. If you have free time, come find me for a date. But please don’t ask me out somewhere, let’s just date at home, okay?”

”As compensation, hmm… I’ll give myself to you…”

”?”

Setsuna confirmed it—Indomitable was indeed the most unusual of the Illustrious-class sisters.

She preferred being passive.

...

The happy party time passed quickly.

One morning—

When Setsuna opened the curtains and saw the sunlight shining over the capital city below, he realized the temporal distortion effect had ended.

Stretching lazily, he still felt a little unsatisfied, though his body told him it was enough.

”Commander, this past month on the Eternal Snowfall was great, wasn’t it?”

Taihou leaned against him from behind and asked.

”Mhm.”

There were so many set meals to choose from aboard the Eternal Snowfall.

Spirit family bowls, black-and-white combo rice, and the Illustrious-class sisters’ combo meal.

It was dazzling to behold.

And when tired, he could enjoy Madam Shoukaku’s care.

Of course, usually that only made him more tired.

Even the three-core system of Allspark plus double Wisdom Cubes had its limits.

”Left arm hugging a big sister, right arm holding a loli—only in the quiet of night do you realize life isn’t easy, tsk tsk.”

Meanwhile, in the living room, Gudako suddenly let out a sigh.

”Tch, loser.”

”Even when the Commander throws a party, you’re not invited.”

Taihou and Jeanne Alter shot her a glance, while some shipgirls deliberately shouted:

”Ritsuka, you’re definitely plotting another night raid on the Commander!”

Gudako widened her eyes: ”How could you slander me out of nowhere…”

”Slander? That day I saw the Commander bathing with Mio, and you used transformation magic to turn into Tohru, trying to sneak in.”

”But then the dragon girl caught you and chased you across the bridge.”

Essex clicked her tongue.

”!!!”

”I didn’t!”

Gudako’s face turned red.

”How can something between Master and Commander be called a night raid?!”

Then came a string of incomprehensible talk—things like ”saving humanity,” ”waiting for the right chance,” ”Heroic Spirits sneaking out,” and ”once I become Grand, I’ll make Commander marry into my family.”

The Eternal Snowfall was filled with cheerful air.

...

A few days later—

Setsuna’s life returned to routine affairs.

During the two months of the Three-Body world expedition, he had entrusted the base’s work to the shipgirls and Angeloids.

They seemed to have managed everything neatly, and the development of outer star systems was proceeding in good order.

He casually pulled up the star map to check the status.

[Civilization Overview]

[Civilization Type: Technological Civilization]

[Technological Level: Space Age (FTL)]

[Territory: 36 Star Systems]

[Population: 85.332 million]

[Species: Humans, Shipgirls, Sirens, Dragons, Catgirls…]

”Wait a second?”

Leaving aside the increase in star systems, the star map showed that the Starsea Empire had already occupied the Solar System and dozens of surrounding star systems.

Across the major planets of the Solar System were traces of Bulins and Angeloids.

They were steadily building footholds and colonies on each planet, developing resources there.

The Empire’s borders stretched nearly a hundred light-years. Not much for an interstellar civilization, but considering that only a few short years had passed since they first ascended to the skies and mastered FTL—it was an impressive achievement.

What shocked Setsuna most was the population count. Compared to the last time he checked, it had more than doubled, rushing toward the hundreds of millions.

”This is the result of implementing Commander’s controllable Bulin-fusion concept.”

Yat Sen explained.

”Previously, upgrading the Juggernaut consumed enormous resources of the Starsea Empire. To supply the raw materials, over a dozen vassal worlds began developing the Solar System.”

”Now that the major fleets have finished refits, resource consumption isn’t as heavy. All surplus materials are being used to create Bulins and Angeloids.”

”Bulins and Angeloids take starships to develop other star systems, and then use the resources they acquire to create more Bulins and Angeloids.”

”No wonder.”

Setsuna understood.

For a civilization controlling dozens of vassal worlds, development didn’t follow a straight, gradual line.

Once a certain threshold was crossed, growth became explosive.

—That threshold was FTL.

Having FTL technology meant quickly developing not only their own system but the surrounding ones.

Hundreds or even thousands of light-years could be traversed instantly. By removing long transit times, expansion speed multiplied.

Before, the main world’s resources depended on the production of a dozen Earths from vassal universes.

Now, by developing those universes, they could pool resources from multiple solar systems, entire galaxies, even entire universes.

With such abundant rear production zones, the Starsea Empire would hardly ever face resource shortages while expanding.

Bulins producing Bulins, Angeloids producing Angeloids.

More Bulins meant developing more planets, producing even more Bulins and Angeloids.

With infinite resources, the two had entered an endless recursion, stepping on their own feet to climb into the sky.

”At the current rate of development, our total population is projected to surpass 100 million in two months, reach 1 billion in two years—”

”And within five years, exceed 10 billion.”

Sophon gave Setsuna a precise projection, then added:

”This is a conservative estimate under the assumption Commander doesn’t acquire additional technologies from other worlds. In reality, it may happen even faster.”

”…”

Yat Sen, Richelieu, and Belfast looked at each other.

”Does anyone remember, when we first arrived in Constantinople, we only had 30 shipgirls and 300 Bulins?…”

”Our world was called Azur Lane, wasn’t it? Why does it feel like the Commander is playing Bulin Lane instead?…”

”We’re a machine empire, aren’t we?! We must be, right?!”

”Good thing.”

Setsuna nodded.

”These are all high-quality populations. The more, the better.”

”We’ll fill every solar system, galaxy, and universe with Bulins and Angeloids!”

—

—

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