Important Author's Note: This work has non-linear chapters, but only for the early part of the story. Also, expect shorter chapters after this one and some unreliable narration. This entire project has been a breath of fresh air to work on, mostly to get it out of my head. Enjoy.

Back straight in a dignified fashion, a young woman walked down the grand halls of one of the many Novus Orbis Librarium headquarters. Her deep, rosy red hair swung to the rhythm of her steps along with the sleeve of her uniform. The night had considerably reduced the amount of foot traffic, but there were still a number of officers dotted around. Like her, they walked with a determined pace as they carried papers and messages to their respective superiors.

Tsubaki, clutching a small stack of papers under her arm, turned a corner towards one of the wings dedicated for office rooms. It was a newly-added extension to the already expansive building, so not many others had been assigned there yet. The absence of people in this area was made known to her without having to look around, as she could only hear her own footsteps echo now.

Past the tall windows lining the sides of the hallway, faint moonlight streamed in behind a curtain of water droplets. Beyond the glass, a unobstructed view from the Hierarchical City's highest level presented itself, currently being assailed by rain.

She slowed down. It wouldn't hurt to admire the ambience alone in silence while she could.

Seeing the waning moon barely peek out from behind murky clouds conjured up thoughts of the Duodecim. Among them were her own family, the esteemed Yayoi. Although she was now a soldier, she still found time during some break days to drop by the estate much like she did during her academy days. The time she reserved then was dedicated to visiting her family and resting, but her latest conversation with her father left a bitter taste in her mouth.

For the first time in her recent memory, she and her father had a disagreement. She had felt a heavy weight push on her chest upon seeing the crease of disapproval on his brows. Standing under the pressure of his gaze, the study room they spoke in had also seemingly kept growing in size.

Letting out a quiet sigh, she looked up ahead. Her destination was nearing close.

…!

Before her thoughts went wandering away again, the strange sensation of being watched froze her in her steps. Quickly putting her guard up, Tsubaki's head turned around in search of who had been looking her way.

But she found nobody, not even a single hint of a figure outside either.

The night had perhaps tired her out more than she realized. For days now, something had been keeping her senses on alert.

Nearly as fast as she had been put on guard, Tsubaki calmed herself and continued on her way. Wherever it came from, the onlooker hadn't given off any signs of being malicious.

A couple of strides later, she arrived in front of a set of decorated doors. The glow from a desk lamp shone through the frosted glass mosaic adorning its centers. With the confidential reports in one hand, she raised her other one to knock. Her knuckles tapped against the solid surface precisely two times to announce her presence.

Tsubaki waited for a response, but none came. After a second round of knocking, she listened carefully. No sound came from the other side, so there must be no meeting of any sorts taking place inside the office. Still, no answer came after another moment.

Wanting to get those papers delivered, she put a hand around the door handle and twisted it. "Pardon me…" she said in a low voice as she let herself in.

Right across the vast room sat a standard office table, while her own was set to the side. Sitting at the central desk was her current superior, Major—

No, that's not right anymore.

Lieutenant Colonel, Jin Kisaragi. It was only some time ago that he had been promoted. With the new rank came new responsibilities, so both of them were transferred to another section of the building.

"Sir?" Stepping in closer, Tsubaki was curious at his lack of response.

A lamp stood near the corner of the table's surface, illuminating the room. The light reflected off of Jin's hair while he had his head propped up against his knuckles. The gentle pattern of his breathing and his closed eyelids were much clearer to see once she got closer.

She nearly gasped out loud upon realizing he had fallen asleep, raising a hand up to her mouth to hush herself. Lowering the tips of her fingers, she then squeezed them. After dwelling on the best course of action, she headed towards her desk. It seemed like she would have to give the reports to him later.

Just when the papers were about to make contact with the tabletop, she caught the sound of him shifting his position.

"...Tsubaki?" As if he had never been asleep at all, he looked at her with an inquisitive air.

"Ah, Jin-niisama! You're awake." Turning around to face him, she smiled.

Only because they were alone did he call her that, so she responded in kind. She would die of embarrassment if anyone outside her friends heard her call her own military senior in such a childish and familiar way while on duty. "My apologies for taking so long."

"No, you returned sooner than I expected. I should be the one apologizing for dozing off." He extended a hand to accept the reports from her.

Softening her expression, Tsubaki laughed as she walked over to his side. Admittedly, she would also have a difficult time resisting the lulling sound of rain at such a late hour.

For a few seconds, Jin flipped through a few of the papers. As his assistant, she already had a general idea of its content. She then saw him setting the reports down behind a stack of sheets which stood nearly four times as thick. Those were due to be looked at first beforehand. On a normal day, the top of his desk sat neat and clear of any form of clutter. The recent days, however, were an exception. After moving to their newly-assigned location, everything had to be placed back into their proper place. All around them, shelves and cabinets sat half-empty. Boxes filled with documents and office supplies remained sealed, pushed to the foot of their tables.

The moving process had also been temporarily complicated by Noel's resignation as a Librarium soldier due to personal reasons, leaving Tsubaki to take over her responsibilities. It was pure chance she knew the former secretary's note-taking and organizational habits, making the transfer easier than most of that type.

Adding to the whirlwind of events was Tsubaki's upcoming promotion not proceeding as smoothly as it should. Because she had switched divisions so abruptly, it delayed the process while putting a limit on her military class. Yet such a setback didn't bother her in the slightest. A new rank added nothing to her current position as a secretary.

Still standing by his side, Tsubaki asked, "Shall we get started then?"

Jin nodded.

Recalling their days at the Military Academy, she returned to her desk with a lighter heart. Jin had always been the type of person to have a sizable amount of work done ahead of time. His diligence could be considered difficult to keep up with by some, but it was no problem for her.

As he began checking and signing some approval forms for soldiers under his unit, Tsubaki took the opportunity to begin her own duties. One of which was to record and organize his meetings in the most optimal way. Following that, she had to help sort through the papers flowing in and out of the room on a daily basis once more. "You're to make an appearance and speak to the graduating students at Torifune in two week's time. So I'll arrange for the check-in meeting with the Intelligence subdivision to happen between the lecture and the reconstruction committee hearings. Is that acceptable?"

And so, they spent the rest of the night in each other's company, steadily chipping away at the paperwork.

When early morning came and the rain subsided, the progress they made went beyond their initial plan. The surface of his desk had been cleared up of the papers overdue for reviewing. All that remained to be looked at were the report she had returned with and the files awaiting in the boxes. Wearied as she felt, the satisfaction of the result made up for the effort.

After fetching some tea along with the latest report of the day, Tsubaki breathed out slowly. Clutching a hot mug in her hands, she stared out at the windows. Past the few drops of water still making their way down and the mountain ranges beyond in the horizon, the sun had begun to show itself. "…"

"Is something on your mind?"

She turned her head with a start. "I must've spaced out again. Were you saying something?"

"I wasn't." After taking a sip, Jin set his drink down. "I simply thought that you seemed...dejected."

"O-oh, did I?" Her tiredness made her dwell on troubled thoughts again. Her fingers clenched themselves. She had been reluctant to share, but having Jin lend an ear was a hard opportunity to pass up. "Well, it-it's my father. We haven't seen each other eye to eye about my decision."

She had been on track to becoming a major—at such a young age no less, a milestone to rival Jin. Achieving that rank meant a great deal for her career, and it was the high marks expected of her as the sole heir to the powerful Yayoi lineage. Despite starting to climb up the ladder, Tsubaki had requested to be moved to the Fourth Thaumaturgist Squadron. With the Librarium being in a dire mess and needing to fill in the holes that have opened up within their common fighting ranks, management eagerly accepted her transfer. To be removed from a notable position and then put under service as a secretary—unsurprisingly, some people would see this as a demotion.

In the eyes of her father, her new post limited her potential and was of no use for serving the Imperator. Furthermore, he took issue with her superior officer. Under normal circumstances, the family name Jin carried should have relieved her family's concerns on her transfer. Unique in the Duodecim, the Kisaragi household was held in rather high regards by her family. In spite of that, the recent news in relation to Jin had definitely soured her father's opinion on him.

"I see." Jin crossed his arms. As someone familiar with the Yayoi leader's reputation, he was sure to understand her implications. "What are you planning to do then? Returning to the Zeroth division would be the most logical solution."

"I refuse!" The clear brownish liquid in her cup sloshed around as she answered with more fierceness than she had intended. Realizing the sudden brazenness of her tone, Tsubaki dipped her head down in apology. "I'm sorry. What I meant to say was I'll have to decline your suggestion. I…I have no intentions of going anywhere in the near future. This is the path I've chosen, and I accept the consequences that result from it."

He looked back at her with some warmth in his eyes. "Of course. If that's what you've set your mind on, then I won't dissuade you from staying."

"Th-thank you!" The way he readily accepted her choice without further discussion gave her a feeling of reassurance unlike any other. Tea still in hand, Tsubaki stared down into it when an epiphany hit her. "Now that I said it out loud…Hah, it was ridiculous to let it bother me so much when I've already made up my mind. I apologize for bringing up such a frivolous topic…"

Returning his line of sight to the thin tendrils of steam rising from his cup, Jin spoke with a light smile, "Heh…I don't have any issues if you simply want to talk, no matter what it's about. Mind you, we're also on break right now, Tsubaki."

A soft heat crept up beneath the skin of her cheeks while the inside of her chest jumped. This had been a frequent occurrence ever since her younger days, which she had learnt to temper with discipline and time spent apart after he had graduated. Yet, it felt like all her training had gone away now that she worked with him, even more so when she saw signs of him thawing from the stone-cold façade he gained in Ikaruga.

With no proper way to answer him coming to mind, Tsubaki settled with an agreeing hum as she brought her tea to her mouth. She felt relieved that Jin took no notice of her fluster. It was only when she looked back that she saw his steely gaze oddly focused ahead, suddenly lost in his own mind. She allowed some time to pass before she tried to bring his attention back to reality. "Jin-niisama?"

He didn't seem to be immediately pulled out of his thoughts by her voice, but he eventually broke the silence. "…There's something I must tell you. You'll be the first to hear it."

"Yes?" The manner in which he said it made her body rigid, bracing for what was to follow.

Closing his eyes for a brief moment, he then exhaled lightly through his nose. "It's about Yukianesa."

The Nox Nyctores existed as one of the most powerful weapons created a hundred years in the past—making it a prized and dangerous relic. At the mention of his sword, Tsubaki then noticed the weapon was nowhere to be found. It usually sat atop a cabinet or leaned against his chair. Wherever and whenever, Jin always had it close at hand. "D-did something happen? Where is it?"

A displeased frown formed on his face. "To put it simply, I don't know. Yukianesa disappeared from my grasp nearly a day ago, and it has since refused to answer my summons."

Her lips pressed firmly together before she parted them to speak. "That's—! I can't believe it…Did it truly vanish without leaving a single clue as to where it's gone? Have you found the cause?"

"No need for panic, Tsubaki. Calm down." Just as he said that, he eased his own expression. "Truth be told, its voice had been rather quiet as of late. I figured Yukianesa's purpose had been fulfilled after the Black Beast's death, thus it was going into a dormant state."

There was a secret only Tsubaki and some other people knew of—Jin's ability to wield any type of grimoire was gone. In the aftermath of the battle, the injuries he sustained along with the strain of pushing his abilities to the limit left his body unable to use any complex form of ars magus. By extension, it meant he could no longer activate the Nox Nyctores nor fight.

The fact he remained inside the Ars Magi Infantry branch was largely due to him being a renowned figurehead who ended the Ikaruga Civil War and dealt the finishing blow to the Black Beast. In order to maintain morale in the NOL and the public after the calamitous appearance of the beast, he was made to stay instead of being transferred elsewhere or honourably discharged.

The news of the weapon disappearing agitated Tsubaki for more than one reason. Although useless as an actual weapon in his hands, the sword served as a signature item for Jin's image. More importantly, Yukianesa was the only personal belonging he had when he joined the Kisaragi family. It was imperative it be located as soon as possible for his sake, stolen or not. "Do you think it's gone for good?"

He shook his head. "No… I still feel a connection to it, but it simply won't respond to me."

"Jin-niisama, I know you're busy, so you can task me to direct an investigation team in your stead. The sooner we recover Yukianesa, the better it'll be!"

His gaze shot her way before casting them down again. "Right, I would also prefer to have it returned to me soon. However…"

"However?" It then occurred to her that his demeanor held little to no sense of urgency.

"Even if we do successfully retrieve it, there is no guarantee it won't vanish again or that it'll respond to me like before," said Jin matter-of-factly.

Tsubaki swallowed, remembering there was little to be done if the sword chose to abandon him as its wielder. "You're right… So, shall I go to report this happening?"

"There's no need. I've already warned the higher ups about Yukianesa's fading presence, so I'll be the one to report this." The look in his eyes, although suppressed, told he was anything but ecstatic to announce his loss of the Nox Nyctores.

"Understood." Not letting her rapidly cooling tea go to waste, she drained the rest of it.

To say she felt devastated when she had first learnt that Jin could no longer fight was not far from the mark. Even now, a melancholic ache rose up whenever she thought about it. At the very least, he was alive and well. Of all people, Jin himself should be the one most upset. Yet, he hadn't shown any kind of regret as if he had already known the result of fighting against the Black Beast. His calm exterior and reassuring words stopped her from shedding more tears than she ought to as a soldier.

From the corner of Tsubaki's vision, she saw him stand up. Raising her head from staring at the bottom of her empty cup, she asked, "Are you heading to the communication room now?" This type of news didn't belong to the public ear, so the usage of relay lines encrypted with special ars magus was a necessity.

"Yes, I want to get this over with and resume our normal duties."

"Of course, sir." By the time he reached for the door, Tsubaki left her own desk to follow him.

As she walked after him, all she could see was his back. The sight brought back memories containing some of her happiest days surrounded by friends, blissfully unaware of the outside world and the trials awaiting them in the future.

Unlike back then, she now carried more reasons to be working as his assistant outside of simple admiration. She was no longer the same girl being blindly moved by her family's and the Librarium's demands. Being the only user of the Zero-Type Izayoi, she had to be mindful of the importance of her abilities. Only a decree from the Imperator or orders from a general would convince her to leave, but only barely.

For the time being, Tsubaki hoped she would get to stay by his side. If Jin could stand with his head held high after sacrificing the skills he spent most of his life honing for the sake of the world, then she would draw strength from his show of fortitude and fight on his behalf.

As long as our paths in this world align, I shall act as your blade in justice, Jin-niisama. As you have shown me light many times in the past, this is my chance at returning that eternal debt.

A silent oath, in honor of the promise made during their lonely childhoods.