Early spring, 1945. The sky was clear in contrast to the atmosphere riding over the harbor.

In spite of the few numbers of people running the place, each kansen was a personified warship with the ability to fight like demigods while requiring little to no maintenance. Their pseudo-magical nature allowed for cost-efficiency the likes of which yet to be seen throughout human history. This allowed the human staff to manage logistics without the usual headaches. After briefing his Division one last time about the upcoming mission, everyone dispersed to follow their own directives. Those with nothing to do, however, seemed to prefer dropping off Ayanami's hull to have a sendoff party with their circle of acquaintances. Left to his own device, Aoto found himself staring down at a letter which he had received from an unexpected guest this morning.

His overall thought about it, however, was unfortunately interrupted when Akagi announced herself through a rather unconventional arrival by floating over from the deck of a warship nearby. As soon as she made her graceful landing, another woman floated down as if following after her—but it was not Kaga. In fact, it was a young woman in a uniform remarkably similar to that of Z23. He almost immediately turned their way to deliver a formal greeting.

"Welcome aboard, though I'm afraid we are not in a state capable of offering some relaxation."

"Good day, Rear Admiral Tatsumiya." Akagi's smile looked the same as always, humble and alluring without a crack. If anything, the fact that her expression did not change even after their last exchange unnerved Aoto, but he did not believe it as wise to point that out. "It seems the briefing is over. I expect there is no complication on that front…"

"Well, we can depart any time, though this will be my first time participating as a part of the attack force instead of the defense force." Aoto tipped his cap so it'd fit in on his head a little bit more. He then glanced at the silver-haired woman. "And a good day to you once again. Iron Blood Heavy Cruiser, Admiral Hipper-class Prinz Eugen."

"Indeed." Prinz Eugen pursed her lips into a smile of her own brand. Unlike Akagi's smile which was in possession of ethereal charisma and hidden depth, this Heavy Cruiser's smile felt predatory, obvious in intent and yet full of sweet temptation. Her gaze hovered on him from top to bottom like a shark who was sizing her prey. "I hope there haven't been any issues between you and our cute junior?"

"Certainly. Niimi-kun is the studious sort, diligent, and also proficient in managing secretary tasks."

As Aoto went off to describe the dynamic between Z23 and his Division, he couldn't help but to tear his gaze away from the four gun ports writhing behind the Iron Blood woman's back. Prinz Eugen strutted and the rigging connected to her moved in tandem, their serpentine joints writhing and slithering like snakes. The rigging seemed to be much more alive than Z23's that it truly made him wonder just what sort of technological marvel was behind such innovation. It also oddly reminded him of the humanoid Siren's rigging in the way that it was neither a true living being nor an exclusively mechanical device.

"...though I feel that it's only because Ayanami is with us that there has been no problem until now."

"A little humble, aren't we?" The Heavy Cruiser tilted her head, a glint flashing through her eyes. "It is well and fine that you can measure your own strength, but such a thing may ruin you all the same."

Aoto let out a small laughter. What a familiar turn in the conversation. "Shoukaku has been nagging about that for quite a while, too. I will strive to be better next time we meet, then."

"Humm? Now that is interesting…" Prinz Eugen mumbled as she came even closer to him. However, she stopped when there were still a few steps away, and she waved while turning in the opposite direction. "Well, I will go and give my greeting to Zed. Do your best out there, Rear Admiral~"

What…? Utterly perplexed, Aoto could only stare at the Heavy Cruiser's shrinking back. The woman had appeared with such a strong gravitas, but suddenly she walked off as if she had lost all interests to pursue the matter. Her mood swings gave him a whiplash. Just… what was her deal?

Akagi's chuckle rang out, "I see that it's the first time you have ever interacted with people like Eugen."

"...are, are there more people like her at Iron Blood…?"

"I'd say yes, though I'm afraid I am not well-versed about their fleet any more than other people. Well, I suppose she is whimsical by nature."

I'm not even sure if whimsical is the right word to call that…

The sea of the Fatherland was cold. After the First Contact War, the Siren spread their influences across the seven seas, claiming territories of their own to conduct whatever nefarious plots they had while ignoring the consequences.

A raging storm without premonitions. Tidal waves of catastrophic proportions. Abrupt formation of islands and archipelago overnight. Extremely unstable climate that defied existing natural laws, and so on. Iron Blood was especially troubled with the dense black clouds, unceasing hail storms, as well as giant edifices that sprouted out of nowhere in the middle of the sea. Even now, Z23's homeland was besieged from all directions as if constantly monitored by their archenemy. Despite the presence and might of the reborn naval force, the Fatherland remained plagued by the Siren's threats. Thus, the need to become stronger became all the more important for the Iron Blood kansen. No matter what happened. No matter the reason... to survive in this chaotic era, to possess strength was a badge of honor, as well as to bear the burden of lighting the path in the darkest hour.

Only the strength you have cultivated will never betray you; such is the creed of—

"Working earnestly like always? My, you're such an honor student."

"Eep!?"

Her reflection was interrupted while she was handling the tactical overlay at the control tower of the ship. It had been decided that Aoto would be there until hours before the battle where he would stay behind alongside the rear line, so there were not many things that needed to fuss over. Still, that voice was unmistakable with all of the faux playfulness. Turning towards the door, Z23 came face-to-face with one of her peers.

"Eugen!?" Z23 almost shouted.

"It's been a while. How're things going on your side, my dear fraulein?" The Heavy Cruiser smiled, this time a lot more teasing in tone. One of the woman's awful traits was to poke, prod, and then press the buttons of everyone she decided to fancy with. Unfortunately for Z23, she happened to be among said group of victims. "I do hope that I'm not intruding, though?"

"Ugh… you always said that after doing exactly that." The Destroyer resigned herself to her fate as she dropped all tasks she must do to prevent any further embarrassment from her side. "You could have at least sent a letter. The headquarters aren't exactly fond of your hobby. Please show some restraints, already..."

"Now, now. I am working as well, you know? No need to worry, I've already taken countermeasures, including for this visitation~"

Z23 promptly gave up, all thoughts of countermeasures cast into the void. When Prinz Eugen said it like that, she actually meant it. It was definitely like her to act so sly and slovenly, but if only she could actually put her act together and use that strong whimsical trait of hers for better use. Still, Z23 had one more trick left. Straightening her posture and clicking her heels together, the Destroyer gave a salute. Prinz Eugen nodded down as she accepted the formal greeting.

"Mhmm. Well, I am simply passing by, but say…" The woman with a pair of burning gold eye colors tilted her head. "The superior assigned to you is something else, isn't he?"

"Pardon?"

"Well, there is nothing exactly out of the ordinary. Appearance and attitude-wise, he seems to be as reasonable as a normal person." Prinz walked back out, prompting Z23 to follow after her. As the two looked over from the catwalk and down at the front deck, the Rear Admiral was now conversing with the Flagship of the Sakura Empire's Combined Fleet. Still, even with their enhanced senses, the winds were being awfully strong and noisy this time. "From his profile, he is a quite talented sailor who has successfully climbed the ranks. A sturdy character through and through, but…"

The lull made Z23 pause. She assumed a ponderous look and then gazed at her superior. "Are you suspecting there is some sort of foul play?"

"Of course not." The Heavy Cruiser giggled. "On the contrary, it all feels… let's see, a little convenient, don't you think? A late bloomer of a Commanding Officer is assigned in a Division infamous for their peculiar characters. As he learns more about his own duty, he also acquired an increasing number of subordinates with varying special backgrounds. The fact that he could still be eligible to command and synchronize with a kansen fleet at his age is already something, but he is now recruited for the war effort in spite of his standing in this empire."

That's…

"Just observe him. It's not that hard since your real task doesn't need you to stand out." Prinz Eugen's smile softened. "Now, how about the upcoming battle? Can you do it, Z23?"

Once again, Z23 was thrown off. Abruptly bringing up a strange topic only to follow it up with another completely unrelated on, Eugen's whim truly had no bounds. Even if she tried to pursue the matter again, she had no doubt the woman would tease her all the way. By that point, either time would be already up or she'd get too exhausted to even bother Eugen. Z23 let out a long sigh through her nose as she sorted her mind.

"Yes. This is all for the Fatherland, and our allies. What I must do… is level my gun and shoot at our enemy—even if they were once my friends."

"...I see."

I see…? Really, what a reaction befitting Eugen. Z23 didn't even know what she was expecting, so she let out a deep sigh. In the following moment, however, the girl felt a hand on her head and she looked up, seeing Prinz Eugen ruffling her hair without saying anything. The flaxen-haired girl widened her eyes, but any thought and word she tried to conjure faded within the silence. It wasn't much of a comfort, but Z23 felt she needed it at the moment.

"Six aircraft carriers. Two battleships. Three heavy cruisers. Five destroyers." Aoto made a thoughtful hum. "At a glance, this force has a weak vanguard. In spite of that, we are in an age where battleships can fight with the agility of destroyers, and aircraft carriers so small it'd be difficult to target from afar."

This composition is awfully geared for aerial supremacy, a very bold strategy right off the bat...

"Your Division will be there to protect our rear line as well as to increase your real combat experience." Akagi slightly tilted her head. "Or could it be you wish to do more than just staying at the back? My, that'd require a complete reshuffling of the fleet formation."

"Please don't assume I'd demand something so unreasonable," Aoto sighed. After the weird meet-and-greet with Prinz Eugen, he felt like he had exchanged a shark with a vulture. Akagi was as elusive as always, but this time she seemed a bit shadier. "I just hope we won't lose anyone."

"Oh? So you are not against fighting fellow humans, then…"

Aoto furrowed his eyebrows. Was she messing with him? No, judging from the inflection of her voice, it seemed the Flagship was genuinely curious about his wording. Identifying the intention of the person speaking with her while having the willingness to openly ascertain the truth… Really, now. Not only a schemer, Akagi possessed the capability to act audaciously whenever it benefited her. Aoto looked out to the sea once again, discarding all other thoughts to answer the expectations given to him.

"I can only save those within the reach of my arms," the Rear Admiral said. "Beyond that line is where God toys with the fates of all creations. I am not so conceited to believe that I am the writer of this outrageous script we call life."

Of course, there was a reason why he could call life as outrageous. Many things flashed through his mind, his own survival being one of them all. Still, outrageous things did not mean they were all bad, though he didn't have the desire to even discuss such a thing. It was boorish of him for sure, not to mention there wasn't anything attractive in talking over the ma—

"...yes, only God can possibly toy around with people and their fates."

Aoto reflexively turned his gaze at the Flagship of the Combined Fleet. There he saw her dipping her head low, a smile plastered on her face, and a gaze bearing intense light. As her giggle wormed into his ears, chills ran down his spine. He had almost given himself to panic before a restraining order was delivered from his brain to his body, experiences, and wisdom allowing him to not expose himself any further to the kansen with the highest authority of the imperial navy. However… he needed to say something; to warn her of just one thing.

"...I hope you are not thinking of anything outrageous as well, Akagi-dono."

"I suppose it shows on my face." Akagi's smile did not falter. As a matter of fact, the air surrounding her was rapidly changing. It became difficult to miss her next words. "Needless to say, I am fully aware of what we are doing, what we are going to achieve, and the repercussions of our actions. But needs must because we cannot allow ourselves to stay like this for any longer."

The woman gazed to the horizon where the sky and the ocean met. An indescribable emotion lurked within Akagi's eyes, one Aoto was sure to never forget even if he wanted to. It was faintly there when he first talked with her, the second time during the festival, and then now. He couldn't say for sure what it was about, but his intuition told him that he was already grasping a few hints about it. Just, if my instinct is correct, then—

"...the tactics are sound," Aoto abruptly switched the topic. "Silence the patrol boats, deactivate the defense arrays, neutralize communication modules, then unleash aerial bombardment over important facilities. The damage will be kept minimum to non-military areas, but I assume your goal is to isolate the Pacific ocean from Azur Lane's grasp."

"Well done. You've noticed, I see." Akagi's smile deepened. "Sadly, it is not perfect. There are three objectives that must be achieved in this operation."

"Three… you say…?"

The primary objective was to declare war against the Azur Lane as well as stating out the Sakura Empire's righteous cause. The secondary objective was to steal the initiative by crippling the first defense line of Eagle Union. Aoto didn't know there was a third objective. What is she...

"The third objective is—to hasten the progress of our empire's research."

Aoto blinked, unable to process for a moment what Akagi just said. However, realization soon dawned and yet another piece fell to fit in the frame. Could it be—

"The Black Cube…" Aoto stared with wide eyes. "You're using this war for… publicity stunt?"

"Not only that," Akagi's smile distorted at that point. As the Aircraft Carrier directed her gaze back to him. Once again the chills returned, but Aoto had lost the initiative. "What we will do… is a large-scale field experiment, Rear Admiral. And we will have our former friends take part in it, simple as that."

The sun soon set, then evening arrived. As the sea calmed down, a number of spotlights illuminating the harbor harshly chased off the darkness. Among the dazzling white curtains were a row of red lights, and the vessels carrying the heavenly mandate sailed off as their identification lights glimmered like the stars in the heavens. Whether or not they'd bring a triumphant return or perish in blazes of glory—nobody could ever know. Fates always had something in store, hiding away the grander pieces of truth from everyone's eyes. But as people entrusted their faith in the power of the kansen, that strange and vague power would sweep the world to become a feast for the gods of the heavenly plains.

"They have… departed, then." A somber voice echoed. "If so, I too shall fulfill my duty."

Deep in the heart of the empire was an island no mortal could ever hope to approach, much less enter at whims. In this most sacred place existed an ancient tree that oversaw the death and rebirth of the world. Ropes tied with charms symbolized boundaries between the impure and the pure, the countless rows of Torii gates emanating mystical energy that permitted only those blessed by the eight million gods. Through the barrier that purified even Siren corruption, several maidens resided within a shrine at the base of the divine tree.

"Onee-sama…" Mutsu wore a pained look as she tugged the sleeve of her older sister. "Please, you can't do this…! It's not your fault that this is happening! You don't have to shoulder the burdens forced on you! There must be… there must be another way!"

Her voice, shrill and disheartened, echoed through the shrine grounds. However, no matter how much tears she had shed, the expression of her older sister did not change for the slightest. A half-lowered gaze full of compassion, a thin smile without strength… it was a mask that had become the Priestess's true face. Nagato reached out to rest her hand on Mutsu's head. Softly, softly, the older sister soothed the pain of her little sister even though both of them knew that their parting would only make this act of kindness feel even more painful.

"It's fine, Mutsu. It's fine…" Nagato lowered her eyelids. "Our era… the age of battleships has come to an end. With people's faith resting on the aircraft carriers, there is no more role for us to play."

"There must be a mistake! We are two of the Big Seven! Our might is not just about firepower!" Mutsu protested. "We can still fight! We are still useful! Surely, surely…!"

As tears dribbled down her cheeks, the younger sister was left out of breaths. Crying and mourning over the present situation, it was just like Mutsu to overreact and get caught up by her emotions.

But that is also why she is so precious, Nagato thought. As her gaze landed on her most loyal retainer, she had never thought that there would come a day where she needed to rely on Kawakaze. There was truly no telling what the world would come to be. Slowly nodding down, the retainer shut her eyes tight before she deeply exhaled. The girl clad in white and green kimono then stepped forward to rest her hands on Mutsu's shoulders. As her little sister sobbed, the retainer called out before telling Mutsu the message that must be said. Her gait was precise with practiced ease after having rehearsed it for countless nights. I'm sorry Kawakaze, for having you go along with my selfishness to the very end.

Nagato had receded the authority as the Combined Fleet's leader to Akagi. With the people's faith in her waning, so did the power that sustained the Sacred Tree. The empire… this homeland of hers was dying, and it was all because of her incompetence. Efforts had been put to no avail. Years after years, the situation did not turn for the better, not even once. Optimism and hope could only lie broken at the end of such a despairing truth. In the end, what must be done was for Nagato to extend the lifespan of the divine tree while Akagi directly commanded the kansen fleet to boost people's faith. Some would say that the trade-off was extremely one-sided, but it suited both Nagato and Akagi just fine. Those who knew of their history would think differently for sure, and above all else...

The very last thing only I could fulfill; my final duty as one entrusted with the people's hopes—

Nagato quietly stepped back. The shallow lake that masked the floor of the shrine grounds created a number of ripples with every step. As she moved further and further away from her sister and friend, she felt her body tugged toward the sacred tree. The moment she was half a step away from fulfilling her final duty, she heard her name called. Nagato gazed down at Mutsu's crying figure as she was finally taken into the bark of the divine tree. Her cheeks grew hot, her eyes blurring as the world seen through her vision distorted like a broken kaleidoscope. Cloths of light enveloped her body, sealing her as well as preserving the state of her being. The girl extended her arm past the magical veil that would forever separate her with the world—

"Thou shalt not touch a human, for they would tarnish thy divinity."

"Thou shalt not smile, for thou must maintain thy dignity."

"Thou shalt not forget; the Creator is your only God."

As she smiled one last time, Nagato pulled back her arm, pressing her hand against the inner veil as if to wave goodbye. Countless thoughts crossed through her mind, but as the rules enforced upon her shackled her, the Priestess discarded all of her opinions so as to become the vessel to contain her people's wishes. In doing so, she knew that she had doomed herself.

I'm sorry, Mikasa-senpai, for failing to fulfill the expectations you have blessed me with.

A lullaby could faintly be heard gradually growing louder as if to sing praises for Nagato's secession of this human body of hers. Her eyelids fluttered shut, her strength fading by the seconds. She first lost her sight, then her sense of touch, taste, smell, even her hurting heart stopped bothering her. There was no pain, thus there was no agony. Because there was no agony, there could be no despair. As she came to that conclusion, Nagato oddly felt at ease. Then, from the depth of the abyss—the ring of voices whispered to her once again.

"Thou shalt not touch a human, for they would tarnish thy divinity."

"Thou shalt not smile, for thou must maintain thy dignity."

"Thou shalt not forget; the Creator is your only God."

The "hymn" suffused her entirety. Over and over again, the three phrases she had heard throughout this new life of hers latched on to her freshly beating heart. However, as she resigned herself to the "voices" of the gods, a few things came to mind. The first was her worry over her sister's future and well-being. The second was a deep regret for that person who had believed in her. Finally… Nagato wondered if she'd see that dream once again, this time for eternity. What would she bear witness to, now that she was giving up everything she had to atone for her sins?

Will I… dream of it once again?

Though she had lost all of her senses, her heart could never forget the past of this world. Though her soul was fading away in order to sustain her homeland, the vision she had been forced to bear witness of could never be erased. The hellfire that burned everything down. The day the heavens raged and the earth cried in anguish. The day the first ill omen befell upon this blue planet. On that fateful, hot summer day, all that she could remember was…

A cruel event that left behind destruction, despair—as well as the footsteps of the one being sung.