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Everyone knew about the legend of the red string.
It wasn’t something you saw at birth, nor something you could trace with your fingers. Most people never saw it at all. They said it only appeared in moments of true danger, when the person on the other end stood at the edge of death, when fate itself decided it could no longer remain silent. That was why it was called the red string of soulmates, and why so few were ever blessed, or cursed, to witness it.
Some believed it was nothing more than a psychological response, a stress-induced hallucination brought on by fear and desperation. Others insisted it was an ancient myth that had survived into the modern age through coincidence and hope.
What mattered was this:
When the red string appeared, it meant one thing and one thing only.
Someone you were bound to was in grave danger.
“So promise me, young man.”
The voice had been stern, unyielding, heavy with something Gen had been too young to name.
“If you ever see that red string,” the man had said, “promise me you will take care of the person on the other end. Because if you don’t… you will regret it for the rest of your life.”
Gen, still training under Shinomiya Isao then, had scoffed, arms crossed tight over his chest, scowl sharp and defiant.
“You’re talking like it’s a fairy tale,” he’d shot back.
But even then, the older man had watched him closely. He noticed the way Gen didn’t laugh. Didn’t dismiss it outright. Beneath the scowl, he listened. A warning taken seriously, even if he’d never admit it. Isao had known it then.
“How would you even know it’s real?” Narumi asked.
Isao didn’t answer right away.
His gaze drifted, not to the past, but through it, resting somewhere far beyond the room, beyond words. For just a moment, the weight in his eyes said everything he refused to put into speech. Loss. Certainty. Regret that carved too deep to explain.
Narumi followed that look, and felt his heart still.
The answer was written all over the old man’s face.
However, those who overcame death to reach each other were remembered.
Their stories survived in fragments, passed down through warnings, half-believed legends, and the quiet looks of those who knew better than to speak too openly. People said that when two soulmates endured that trial, when both ends of the red string refused to break despite fate’s interference, the bond between them became irreversible.
They said that being soulmates meant more than destiny.
It meant connection.
Heart and mind intertwined, tuned to the same frequency. From the moment the bond was formed, something unseen but undeniable was established between them, like two separate pieces finally becoming whole. The pull could be subtle or overwhelming, a constant awareness that never truly faded. In rare cases, soulmates could even hear each other’s thoughts. Not words exactly, but impressions, emotions, intent bleeding through like echoes in the mind.
A shared awareness.
Your soul would recognize the other long before your mind caught up. It would yearn instinctively, tugging you closer even when distance demanded otherwise. In the presence of your soulmate, everything else, logic, restraint, and even the instinct to protect yourself, became less important.
And when the red string finally revealed itself, it was no longer just a warning.
It was a demand.
Because fate, once it had bound two souls together, would not accept separation.
It was not like the other missions.
Narumi had led joint operations before. He knew the rhythm of coordinated divisions, the ebb and flow of combat, the moment when pressure either broke or bent. This, however, was something else entirely.
With Hasegawa’s support, he stood at the forefront of the battlefield, commanding the joint forces of the First and Third Divisions, and things were unraveling. Not because of poor leadership nor was it because of miscalculation.
The enemy simply refused to thin.
Kaiju kept coming, wave after wave tearing through the ruined district like a living tide. And these weren’t the smaller, disposable types meant to test defenses. Most of them were honju-class, fortitude ratings climbing past five, six, some pushing even higher. Each one demanded focus, resources, time they no longer had.
The First Division held one submerged point. The Third held the other.
“Most likely there’s a master controlling them,” Hoshina said through the shared comms. “It won’t be easy, but with Okonogi-chan’s help, I might be able to locate it. In the meantime, Captain Ashiro, Captain Narumi, apologize but I’ll have to bother ya both with holding the line without me. There’s a chance it’ll show itself at either location.”
“Copy that,” Ashiro replied calmly as she loaded another round into her weapon.
Narumi clicked his tongue. “Tch. It’ll be over before you even find it, bowl-cut. You better still be alive so I can rub it in your face.”
“How nice of ya to care about little ol’ me, Captain Narumi~” Hoshina replied, the teasing smirk audible even through the static. “Don’t worry so much, Capt.”
Narumi scowled. “Just don’t die before you report back.”
But things didn’t go the way they planned. Not long after Hoshina went solo, another problem occurred.
The daikaiju Ashiro had just taken down released a dense gas, not lethal, but disruptive enough to jam communications and blind visual feeds. Narumi cursed under his breath, silently thankful for his kaiju retinas.
“Status update,” Narumi barked into the comm, eyes tracking another massive silhouette bursting through smoke and concrete. Static crackled and there’s nothing but overlapping interference.
The kaiju numbers began to thin, yet there was still no word from Hoshina.
As much as he hated to admit it, he trusted Hoshina’s skills. Even alone, even stalling for backup, the vice-captain could hold his own. But Hoshina had a habit of pushing himself too far, disregarding his own safety for the sake of others or for the sake of completing the mission.
Narumi hated and admired that about him.
His patience wore thin, unease curling tight in his chest. Something felt wrong. Still, all he could do was cut through the kaiju in front of him and keep moving.
This is getting nowhere, I have to find Hasegawa and regroup, thought Narumi. He trusts Kurusu and the operation team to deal with the communication and the gas cloud as soon as possible.
After clearing all the kaijus in his vicinity, Narumi was about to activate his RT-0001, but suddenly he could feel a faint tug on his wrist.
“Huh?”
He spun, bayonet snapping into position as his retinas flared to life, the world resolving into threat markers and heat signatures.
Nothing.
No movement. No immediate enemies. The area around him lay in fractured stillness, collapsed buildings, drifting dust, scorched asphalt. Kaiju signatures pulsed faintly far to his left, distant enough not to register as an immediate threat. There shouldn’t have been anyone or anything close enough to reach him.
And yet—
The tug came again on his wrist. Stronger this time.
Narumi staggered a half-step to the right, breath hitching as something tight wrapped around his wrist and pulled. His eyes snapped down instinctively.
“...A red string?”
A red strand that wasn’t there before now wrapped itself securely around his wrist, faintly luminous, pulsing in a steady rhythm, almost like a heartbeat. It pulled insistently eastward, taut, as if anchored to something far beyond his line of sight.
For a brief moment, Narumi could only stare. He was stunned, but somewhat mesmerized. A certain memory came from the old man resurfacing in his mind, a warning about a myth that shouldn't exist in real life. About fate. About soulmates.
His soulmate.
His mind scrambled, trying to rationalize what his eyes were seeing. Is he lucky to have one? Or unlucky enough to see the proof of it like this?
Then understanding hit him all at once and Narumi’s blood ran cold.
No, wait, if this string shows up, that means–!
The string yanked again, harder this time, snapping him out of his daze.
And with that, Narumi didn’t hesitate. He ran.
Fast.
He followed the pull without hesitation, boots pounding against broken ground, bayonet clenched tight in his trembling grip. The thought burned sharp and clear in his mind now, undeniable.
If a red string appeared on his wrist,
It meant his soulmate was in danger.
He activated his retinas, scanning through the haze as he ran, searching for the signal he hadn’t been able to name until now. What felt like far too long passed before the terrain abruptly opened up.
Narumi burst into what had once been a residential district, rows of buildings reduced to rubble, streets torn apart and unrecognizable. Concrete slabs lay scattered like broken bones, dust and debris still drifting through the air from recent impacts.
And beyond what normal eyes could see, Narumi saw it.
There.
A familiar electric signature flickered at the edge of his vision.
That body signal—
A roar tore through the air, violent enough to rattle the ground beneath his feet and a daikaiju loomed ahead.
It towered over the ruins, its massive frame blotting out what little light filtered through the smoke, jagged limbs braced against the remains of a shattered structure. Its jaws opened wide, rows of teeth slick with dark fluid as it leaned down toward something, no, someone, trapped beneath it.
Narumi’s breath caught.
The red string burned taut around his wrist, pulling him forward, leading him unerringly to a single figure laying weakly on the ground, bloodied and barely moving save for the shallow rise and fall of his chest.
Hoshina.
The realization hit harder than any blow.
It was a rare sight, seeing his rival, the man who could always match his pace and sometimes even surpass him, brought this low. The lower half of Hoshina’s uniform was shredded, one ankle twisted and blood seeping into the dust below. Sections of the No. 10 suit were scratched and torn, its once-formidable armor reduced to cracked plating and exposed seams. He would laugh at the prideful sentient battle suit if it’s not the dire state the wearer is in.
The twin blades were nowhere within reach. A long blade lay snapped in two, its broken hilt still resting loosely in Hoshina’s palm, fingers curled as if he’d refused to let go even after losing consciousness.
Hoshina wasn’t moving.
If not for No. 10’s tail braced against the daikaiju’s neck, holding it back through sheer force of will alone, Hoshina would have already been devoured. Even that resistance was failing. Narumi could see it. The blue light along the armor flickered, dim and unstable.
Then, faintly, a strained voice crackled through the suit, distorted, and barely holding together.
“Hoshina’s… mate… here… good…”
The light went out and the tail slackened.
The red string yanked hard, pulling Narumi forward as his eyes widened in horror.
“No—!”
The moment the tail fell slack, Narumi moved.
There was no warning given. Body moved on his own as he launched himself forward, boots tearing into the broken asphalt as the red string flared hot against his skin, pulling him straight toward the daikaiju like a tether drawn too tight.
The creature turned, sensing movement. Too slow.
Narumi drove his bayonet clean into the joint beneath its jaw, the impact shuddering up his arm as he twisted hard and fired. The blast ripped through flesh and bone alike, spraying dark ichor across the rubble as the daikaiju reeled back with a thunderous roar.
“Get away from him,” Narumi snarled, voice low and vicious.
The kaiju lashed out blindly, jagged limb carving through the air where Narumi had been a heartbeat earlier. He slid beneath it, boots skidding through debris, and the red string yanked, sharp and insistent, jerking him just far enough that the blow missed by inches.
It burned. Not painful, exactly, but unbearable in its urgency. Each pulse of the string sent something foreign crashing through his chest, panic that wasn’t his, pain that wasn’t his, a flickering awareness that felt frighteningly close to thought.
Too weak. Cold. Not much time.
Narumi grit his teeth as he jumped back from the kaiju and stood in a guarding stance in front of the unconscious man, protective and alert. He glanced back, eyes full of worry and pain from seeing the state Hoshina in.
“I’m here,” he muttered, whether to the string or the man behind him, he didn’t know. “You’re safe now.”
He rushed back to the kaiju and vaulted up its arm as he detonated another shot point-blank into its shoulder, then used the recoil to propel himself higher. The daikaiju howled, thrashing, but Narumi was already moving, every strike precise, merciless, driven by something deeper than training.
You’re not dying on me, he thought fiercely.
Not now. Not when I finally know it’s you after all this time.
Far from the clash of steel and roaring flesh, the man pinned near the ruins stirred.
Hoshina’s consciousness surfaced slowly, painfully, like breaking through thick water. He couldn’t feel most of his body. His armor—usually loud and annoyingly talkative—was silent, its presence reduced to a distant, dull pressure around him. No warnings. No commentary. Nothing.
But he could hear something.
The faint echo of battle. Explosions. A voice cutting through the chaos, familiar enough that for a moment, he thought it couldn’t be real. And beneath it all, a presence that tugged at him, made his chest ache in a way that had nothing to do with injury.
The only thing he could feel clearly was his left wrist.
Something held it. Not painfully. Not tightly. Just… there. Steady. Warm.
Hoshina frowned faintly, eyes fluttering open just enough to focus. A thin strand of light was wrapped around his wrist, glowing softly, pulsing in a slow, reassuring rhythm, as if it were alive.
“…A red… string…?”
The glow pulsed once, stronger, then weakened.
Hoshina’s vision blurred, the edges of the world smearing together as pain finally caught up with him. The red string tugged faintly, like a hand squeezing his wrist in reassurance, and in that brief moment of clarity, understanding settled in his chest with quiet certainty.
So it’s you…
A soft breath left him, more relief than sound. His fingers twitched around the broken hilt still resting in his palm, as if trying to hold on just a little longer.
Figures, he thought dimly. Of course it’d be you.
The glow dimmed.
And then Hoshina slipped back into darkness, the red string still wound around his wrist, unbroken.
“You must never disobey fate,” a stern voice said, echoing through the dark. “For you will find yourself standing at death’s door.”
Fate was not something his family treated lightly. In the Hoshina household, it wasn’t spoken of as romance or blessing. It wasn’t poetic. It was law.
“Fate does not ask what you want,” his father had said, eyes sharp, unyielding. “It tells you what must be done.”
Soulmates, especially, were not something to chase.
They were something to endure.
A bond that could strengthen you, or destroy you, depending on how you responded to it. To the Hoshina family, the red string was not a promise of happiness, but a responsibility. A warning wrapped in myth.
“If the string appears,” his father continued, “it means your life is no longer only your own.”
Hoshina remembered nodding back then, too young to argue, too proud to ask questions. He had accepted it the way he accepted everything else: as something he would deal with when the time came. He never thought it would.
Because Hoshina had never been one to bow to fate.
Not when his father told him to quit the Defense Force. Not when the higher-ups ordered him to pack up his blades and go home. He had always met fate head-on, dealt with whatever it threw at him, soulmate or no soulmate.
He just never imagined he would be the one lying at the edge of death, the red string wrapped around his wrist like a quiet accusation.
In the darkness, Hoshina’s consciousness drifted.
And somewhere deep within it, the warmth at his wrist remained, steady, undeniable.
Fate had found him.
And for the first time, Hoshina wondered, not with fear, but with something dangerously close to acceptance and what it meant to stop running from it.
Hoshina wasn’t sure how long he had been unconscious.
Time felt loose, unmoored. But beneath the fog of his awareness, something steady pressed close, fierce and warm, refusing to let him drift too far.
Someone was there.
That familiar presence he knew too well. The one he felt whenever he fought alongside someone who could keep up without hesitation. Reckless. Loud. Irritatingly bright, and yet unwavering when it counted.
Narumi.
The name surfaced without effort, without question.
With it came something that made his breath hitch weakly in his chest.
Fear, yet not his own.
I won’t let you die.
The thought wasn’t spoken, but it settled into Hoshina’s mind all the same, solid, immovable.
Idiot…
The corner of his mouth twitched, almost a smile. Of course it would be Narumi. Of course fate would be cruel enough, and foolish enough, to tie him to someone like that. Someone he argued with constantly. Someone who pushed every button he had.
And yet, someone who never once turned away. Someone who saw him clearly far beyond what others see in him.
Please wake up…
The warmth around Hoshina’s wrist tightened, grounding him. Anchoring him to the present. To life.
Gradually, the world began to take shape around him. The low hum of generators. Soft, hurried voices. The smell of antiseptic layered over dust and blood. Something firm but padded beneath his back instead of shattered concrete.
A medical tent.
Hoshina’s eyelids fluttered. Light filtered through the canvas overhead, too bright at first. He squinted, vision swimming, body heavy and unresponsive except for the dull ache reminding him he’d survived by a narrow margin.
And then he felt it, clearly this time.
A hand had been wrapped around his own the entire time.
Steady. Unmoving.
“Ngh…” The sound slipped out before he could stop it.
The grip on his hand tightened instantly.
Hoshina struggled to open his eyes, but he didn’t need to. He already knew who it was.
After a couple minutes of adjustment with the bright light of the tent, the sight of Narumi looking disheveled and tired but relaxed greeted him. For a second there, Hoshina thought he looked cool.
“Took you long enough,” Narumi muttered, voice low, rough at the edges. Too close to relief to bother hiding it. “You’re a real pain, you know that?”
Hoshina exhaled softly, the smallest hint of a smirk tugging at his lips. Eyes flickering open weakly. Yeah… I know… I’m sorry…
The bowl-cut didn’t exactly phrase the word, but Narumi frowned, like he’d heard it just the same.
“No, you’re not,” Narumi said immediately, grip tightening just a fraction. “You said I don’t have to worry about you, yet—”
His voice dropped, steadier now, quieter, as if speaking too loudly might make Hoshina disappear again.
“You nearly got yourself killed doing it.”
The words should’ve sounded like a scolding. Yet they didn’t. There was no heat in them, only something tight and unspoken beneath. Fear, raw and barely contained.
Narumi doesn’t show it, but Hoshina could feel it now, unmistakably, through the bond between them. The worry Narumi never showed, the terror he always buried beneath scowls and sharp words. It had always been there.
Hoshina managed a quiet huff of air. So harsh, Captain…
Despite himself, a smile curved across his face. Small. Fragile. Real.
It made Narumi’s chest ache.
Then something warm pulsed between their wrists.
Both of them looked down.
A red string lay intertwined around their joined hands, glowing faintly as it bound them together.
Their red string.
Narumi was the first to break the silence.
“So…” He scratched the back of his head with his free hand, the other still firmly holding Hoshina’s, unwilling to let go despite the faint, awkward tension hanging between them.
“I wouldn’t have expected it to be you,” he admitted. “If I’m being honest.”
The vice-captain let out a weak, breathy laugh.
“Me neither…”
Narumi huffed, then shifted slightly closer without seeming to realize it. His thumb brushed over Hoshina’s palm, gentle and almost reverent.
“But,” he said quietly, eyes fixed on the string between them, “I’m not surprised it’s you.”
Hoshina’s breath hitched.
He felt the warmth rush to his face before he could stop it, he caught the faint pink creeping along Narumi’s cheeks too. Through the string, through that shared pulse, he felt it. Narumi’s heartbeat, quick and unsteady, gradually falling into rhythm with his own.
The pull between them wasn’t urgent.
It was patient, steady yet filled with anticipation. Like something that had been waiting a long time to be acknowledged.
They could both feel it. That this want had always been there. Ever since the first time Narumi had asked Hoshina to join the First Division, impressed by his strength. Ever since the moment Hoshina had stood frozen, mesmerized, watching Narumi subjugate a daikaiju all on his own.
There was no hiding it now. The red string laid their feelings bare, leaving nothing unspoken between them.
Hoshina swallowed, throat tight. “So this is it,” he murmured. “The thing my family warned me about.”
Narumi glanced up at him. “You scared?”
Hoshina considered it for a moment then he shook his head, just slightly. “No. Just… surprised fate has a sense of humor.”
That earned a quiet snort from Narumi. “Tell me about it.”
He hesitated, then tightened his grip. Not possessive, not demanding, but a silent promise.
“I don’t know what this means yet,” Narumi said. “And I’m bad at… this kind of stuff.”
Hoshina smiled, softer this time. “Yeah. I noticed. ”
Something—instinct, maybe—pulled him forward. Their foreheads brushed together, tentative, close enough to feel each other’s breath. Their bond was new, but Narumi’s body already yearned to be close to his soulmate.
“But,” Narumi continued, voice firm despite the blush still lingering, “I know one thing.”
He met Hoshina’s gaze, steady and unflinching.
“I’m not letting go.”
Maybe fate hadn’t started their connection. Maybe it had only guided them into each other’s orbit. But for the first time in his life, Hoshina didn’t feel like fate was a chain around his wrist.
It felt like a choice.
Narumi hesitated just for a heartbeat, and then leaned in, slow and careful, as if giving Hoshina every chance to pull away. When he didn’t, Narumi pressed a soft, tentative kiss to his lips. Nothing rushed. Nothing desperate. Just warm, steady reassurance, like a promise spoken without words.
Everything clicked into places. Two separate pieces finally becoming whole.
Hoshina’s chest tightened as emotion surged all at once—relief, happiness, lingering fear—so overwhelming it nearly brought tears to his eyes. He clung to the moment, unwilling to let go, and Narumi was the same, until the need for air finally forced them apart.
Hoshina drew a steady breath, then leaned in just enough to rest his forehead against Narumi’s.
“...Me too,” he said quietly, the decision settling firm and certain in his chest. “I don’t wanna let go.”
It was an answer he could finally give, one he chose for himself after a lifetime of being told what fate demanded of him.
The red string around their wrists pulsed once more, soft, satisfied, before slowly fading from sight. It didn’t disappear completely. They could still feel it there, an invisible tether humming beneath their skin, binding them together in a way that no longer needed to be seen.
They stayed like that for a moment, lost in each other’s eyes, until this time Hoshina is the one who broke the silence.
“So,” he murmured, voice light despite everything. “What now?”
Narumi scratched his cheek, a little sheepish, ears faintly red. “Well… maybe after you fully heal,” he said, glancing at the bandages and then back at him, “I could take you out on a date?”
Hoshina blinked. “A date?”
“Yeah,” Narumi said, squeezing his hand, nervous clearly radiating from the said-strongest captain. “And then you can decide if you wanna accept me as your boyfriend or not.”
Hoshina laughed, soft, genuine, and full of warmth.
“I think we’re way past ‘boyfriends,’ Captain,” he said fondly. “But… I’d love that.”
Narumi grinned, bright and unapologetic.
Yeah.
This time, fate didn’t feel like something to obey.
It felt like something they chose. Together.
Extra scene:
Narumi decided exactly three minutes later that this soulmate thing was a mistake.
Not the Hoshina part. Never that.
The hearing-each-other’s-thoughts part.
He sat beside the medical bed, posture stiff, arms crossed like that alone would stop his brain from betraying him. Hoshina lay propped against the pillows, awake but still clearly recovering, eyes half-lidded and annoyingly sharp. However, Narumi's eyes wandered from the fox-like eyes to the lips he just kissed previously.
Okay. Don’t think about the kiss before. Just act normal.
—You’re staring.
Narumi flinched. “I am not.”
Hoshina hummed, unconvinced. “You are.” At my lips even.
Narumi cleared his throat and looked resolutely at the IV stand. “Medical observation.”
Liar.
—Hey—! That wasn’t intentional!
Hoshina blinked, then slowly turned his head. “You heard that one too.”
“…Yeah.”
They stared at each other.
The red string, wrapped loosely around their wrists, pulsed once, soft and smug.
Hoshina pressed his lips together, shoulders shaking faintly. “This is… going to take some getting used to.”
You’re telling me.
Narumi grimaced. “Can we set some ground rules?”
Hoshina tilted his head. “Like?”
“Like, don’t listen when I’m thinking.”
—That defeats the purpose.
Narumi scowled. “Then don’t comment on it.”
Hoshina smiled. “No promises.”
Before Narumi could retort, the tent flap rustled.
“Vice-Captain Hoshina?” a medic’s voice called. “Just doing a routine check—”
The moment the medic stepped inside, Narumi straightened automatically, expression snapping into professional neutrality.
Too late.
—Oh, he’s handsome…
Narumi’s jaw clenched.
The medic approached the cot, clipboard in hand. “Good to see you awake, sir. How are you feeling?”
Hoshina gave a polite smile. “Still alive. So that’s good.”
“Glad to hear it.” The medic chuckled lightly, then glanced down at the vitals monitor. “You gave us a scare out there.”
—He’s smiling at you.
Narumi’s eyes twitched and Hoshina blinked at Narumi’s thought to him.
Hoshina felt the sharp flare of irritation through the bond and had to bite back a grin.
“I’ll need to check your injuries,” the medic continued, reaching toward Hoshina’s arm.
Narumi leaned forward instantly. “He’s still fragile.”
The medic blinked. “I—yes. That’s why I’m—”
—Why is he touching you?
Hoshina coughed at the comment.
—Captain, it’s literally his job.
Narumi glared. —I know that.
The medic looked between them, confused at the silence and yet the First Division’s captain just glared harder at him. “…Is this a bad time?”
“No,” Hoshina said quickly. “He’s just...”—Jealous.
Narumi froze.
Hoshina absolutely lost it.
A laugh burst out of him before he could stop it, soft but unmistakable.
Narumi’s face went red. “I am not—!”
The medic slowly lowered his clipboard. “…Should I come back later?”
“Yes,” Narumi said immediately.
“No,” Hoshina said at the same time.
They looked at each other.
Hoshina smiled, eyes warm and teasing. “Sorry. He’s… adjusting.”
—You’re enjoying this.
—I am, Hoshina replied sweetly.
The medic cleared his throat. “Right. I’ll… give you two a moment.”
As the tent flap closed behind him, Narumi sank back into his chair with a groan. “This bond is a menace.”
Hoshina reached out, squeezing his hand gently. “You didn’t deny it.”
Narumi looked away. “…Deny what?”
—That you’re jealous.
“…Shut up.”
The red string pulsed again, warm and steady, as Hoshina laughed quietly. Content, alive, and very much not letting Narumi go.