Prelude: Harmonia

[November 15th, 07:58 JST]

Tokyo Prefecture – Harmonia Foundation Tama Facility, West Corridor

The corridor lights hummed softly, their pale glow stretching across polished marble. Reina and her team were already in uniform: the white military-style coat with black undersuit, blue trim, and high white boots that marked them as Aria Corps Team 02, Tempesta Unit.

Emi walked ahead, her hands steady on the wheelchair handles as she guided Reina down the hall. The leader’s leg still refused to move, the feedback of the Coda Cantus lingering like a phantom weight. Their footsteps echoed faintly in rhythm, the sound crisp against the sterile stillness.

It was still early, yet the corridors were alive with motion. Researchers, officers, and technicians passing by with quiet precision between rows of identical meeting rooms. No one gave them a second glance; Divas in uniform were as common here as lab coats and ID badges.

They stopped at one of the doors. A polished wooden panel, unmarked except for the silver plate beside it: MEETING ROOM ZERO-ONE.

Reina’s gaze held steady. Without hesitation, she pushed the door open — an action practiced, almost ritual, as if she’d done this a hundred times before.

Inside, the meeting room carried the same clinical polish as the corridors, its white walls and the low hum of the air-conditioning giving the space a cool, calming feel. At its center stood an oval conference table surrounded by sleek black chairs, a projection screen idling at the far end.

Takeshi was already there, tablet in hand. He looked up and offered a faint smile as the girls entered and took their seats, a quiet morning greeting. Reina was positioned near the head of the table in her wheelchair, angled toward the entrance.

Silence settled fast. Even Nana, usually the first to break tension, sat still with her hands folded and eyes lowered, waiting.

A soft tick echoed from the wall clock. When it struck eight, the door opened.

An older man stepped inside, tall and broad-shouldered, his black hair streaked with gray. A thin eyepatch covered his right eye, giving him a presence that needed no exaggeration. His suit was immaculate — black jacket, white shirt, silver tie. Every motion spoke of authority carved by years of command.

All six girls rose at once in unison. Takeshi bowed low in respect.

Reina simply nodded, her gaze steady and familiar, respectful in a way that felt more like greeting an old comrade rather than a superior.

“Good morning, Director Kurogane.” She said quietly.

The man’s remaining eye glinted faintly in approval as he closed the door behind him.

For a moment, he said nothing. The faint click of the door latch echoed through the room like a metronome marking silence. His gaze swept across the table, moving from Emi’s calm focus to Nana’s forced composure, from Misaki’s steady mask to Reina’s unflinching stare. 

Only then did he speak, his commanding voice deep.

“Good morning. Tempesta Unit. Let’s begin.”

“On November 13th, we conducted an operation in Nagano Prefecture to secure Meteorite ID-117. CODA readings spiked around twenty-two hundred hours, and Tempesta Unit was deployed alongside JGSDF to evacuate civilians and protect the Foundation’s extraction team.”

The projector at the front flickered to life, bathing the room in cold light. Satellite footage filled the screen — grainy images of a small town swallowed by fog.

Director Kurogane nodded once, silent.

Takeshi continued, his tone clipped and professional.

“During the evacuation, two JGSDF personnel were caught by Level 1 CODA. Conventional firepower was ineffective, as expected. Tempesta responded and neutralized the threat.”

Kurogane’s gaze shifted toward Reina. His expression did soften, but a spark of approval lit his eye, unspoken yet clear. She met his stare with a small nod.

“The situation escalated soon after,” Takeshi went on. “CODA signatures rose exponentially — roughly five thousand entities with ten confirmed Level 3s. The cause was uncertain at the time.”

Reina exhaled quietly. “Was it the meteorite?”

Takeshi hesitated, then nodded. “Yes. Based on post-operation analysis, the fragment resonated with your Cantus frequency. It drew the horde to you.”

Her heart sank. So it was me. The guilt flickered across her eyes before she could hide it.

Takeshi caught the look and quickly added, “That resonance was unique, Tachibana-san. There’s no record of it happening before. Don’t overthink it.”

The screen faded to black. Takeshi powered down the projector, then pulled a thin document folder from his briefcase and slid it across the table toward the director before setting his tablet aside.

“All mission data, performance records, and the Coda Cantus analysis have been submitted. Miyagawa-san’s Ars Aria played a key role in stabilizing Captain Tachibana during extraction.”

He turned slightly toward the director. “That concludes my report.”

The director remained still, flipping through the documents before him. Only the faint sound of paper filled the room. Then he spoke.

“You did well.”

His voice was low and gravel-edged, but not unkind. “All of you.”

Relief rippled quietly through the girls. Even Nana, trying to hide her grin, straightened in her seat.

Kurogane’s gaze rested on Emiko. “Miyagawa-san. Your Cantus—Lux Cantus, was it? Excellent control for someone your age. I can see you reaching Cantus Major grade one day.”

Emiko’s cheek flushed. “Th-thank you, Director.”

He nodded once, then looked back to Reina. “As for you… I assume your condition remains unchanged?”

Reina shifted slightly. “The doctors say the paralysis will fade with time. I can still sense my resonance, but it’s faint.”

Kurogane leaned back in his chair, folding his arms. “Good. Rest, but don’t grow idle. Tempesta Unit will remain on standby until you’re fully recovered.”

The girls exchanged glances, caught between disappointment and relief.

Then his tone softened, almost as if the next line wasn’t part of the official agenda.

“One more thing. This isn’t an order from the board — it’s from me. Until you recover, I want you to serve as a mentor for the new Divas entering the Foundation’s program. Aria Corps is now an official initiative, and recruits are flooding in. Someone has to teach them what real combat means.”

Reina hesitated. “A mentor…?”

“You’ve faced what none of them have. That experience is worth more than any manual.”

Her eyes lowered. The idea of teaching while half-paralyzed made her uneasy, but across the table, Takeshi’s quiet nod and the faint, encouraging smiles of her teammates said everything.

Finally, Reina sighed and nodded. “Understood.”

Kurogane smiled faintly, the expression barely there but genuine. “Good. That will be all for now.” He rose. “Tempesta Unit, dismissed. Tachibana-san, stay for a moment.”

The girls stood, saluting before filing out, with Takeshi being the last one. The door closed softly behind them, leaving only Reina and Kurogane in the quiet hum of the room.

Kurogane’s strict expression softened, the authority fading from his face until only the man remained — a guardian who had raised her. For a moment, he looked less like the director of the Harmonia Foundation and more like an uncle watching over his niece.

After Reina’s parents died, Kurogane took her in. To everyone else, she was just another orphan that was scouted by the Foundation due to her unique resonance power. Only Takeshi knew the truth, because Reina had told him herself.

Kurogane exhaled quietly, folding his arms. “Reina, how do you feel? Coda Cantus was never meant to be sung, according to the murals. You know that.”

She met his gaze with her pale cerulean eyes. “Maybe. But the theory was a Cantus Major-grade Diva could withstand it. And here I am, living proof.”

He frowned. “Even so, there’s too much we still don’t understand. I’ll be instructing your producer to forbid you from singing it again.”

A small smile touched her lips, more defiant than playful. “You know I’ll sing it again if I have to. You can forbid me, but you can’t stop me.”

Kurogane sighed, rubbing the bridge of his nose. “You’re still the same stubborn girl I raised.” His voice held a note of weary affection.

Reina’s smile faded. “Oji-san… do you think that meteorite reacted to me because of the CODA frequency inside me?”

He paused before answering. “I don’t know. What I do know is that Project Harmonia had to be activated to save you after that incident. You lost control of your Ars Aria. You were dying, Reina. We barely brought you back.”

Silence hung between them, heavy with the weight of unspoken things.

Reina lowered her gaze. “I see.”

He nodded once, his tone softening again. “That’s enough talk for today. Rest. The world can wait a little while longer.”

Reina nodded silently. What was done was done. She turned her wheelchair toward the door.

“I’ll see you later, Director”

Kurogane’s voice followed her as the door clicked open. “Your class starts tomorrow at nine. Lecture Hall Zero One. Good luck, Tachibana-san.”

She smiled faintly without looking back, the expression brief but real, and pushed herself into the quiet hallway.

As the door closed, the sound of the hallway returned: distant chatter, the hum of lights, and footsteps against the marble floor. Her teammates were waiting for her on a bench not far from the meeting room. Reina wheeled herself toward them, slow and steady, her thoughts already drifting to tomorrow.