hello! i’ve been talkin bout this a bit already but i’m going to turn undermattsun into a multifandom blog! which means my non-hq sideblogs, namely underyuuta will be used more as an archive. i’ll still be using underkita, which will probs also become multifandom (but for all the non dark content purposes)!
anyway, pls be patient w me as i work on makin m.lists and figuring out other organization stuffs.
that being said, the fandoms i’ll be mainly writing for will be: haikyuu (surprise surprise), jujutsu kaisen, attack on titan + maybe obey me
once i get my rules together i’ll outline other fandoms i’m down to talk about + update if i change my mind about which ones i’ll be writing for!!
a/n: this is an old old wip that i dug out from the depths and finally finished bc it’s what yuuta deserves <3 this is a soulmate au btw!
dedicated to @bakatenshii this can be ur,,, bday? early christmas?? somethin gift??
18+ adult characters
warnings: INCEST, slight panic attack, feelings of jealousy, just a lot of feelings in general, angst? kinda sorta?, gojo satoru always needs a warning
a/n: this is an old old wip that i dug out from the depths and finally finished bc it’s what yuuta deserves <3 this is a soulmate au btw!
dedicated to @bakatenshii this can be ur,,, bday? early christmas?? somethin gift??
18+ adult characters
warnings: INCEST, slight panic attack, feelings of jealousy, just a lot of feelings in general, angst? kinda sorta?, gojo satoru always needs a warning
The words of your mother ingrain themselves on the left side of your brain at the age of seven. Her hands cupping your face to force your gaze to meet hers after watching you stare warily at the red string fixed to your right pinky is stowed away as the faintest of memories.
Your eyes, they’re different. They’re special.
Her voice was low, making a point to look around quickly in search of wandering eyes and ears.
Tell no one.
It’s said like a promise, one to keep forever. It’s easy enough to keep it away from everyone, only difficult when it comes to him.
At eight you ask the question they had been dreading.
“Mommy, why does the red string lead to Yuuta-nii?” The pen falls from her hand, recoiling as if it’s burnt her fingers, eyes widening at the innocently spoken inquiry. Her silence is deafening, each second spent under her scrutinizing gaze only filling your young mind with confusion and perhaps fear.
“Best friends, you’ll always be best friends. That’s what it means.” She nods her head, words more poised to convince herself more than anything. At eight you don’t think to question it, why would your mother lie?
“She must be confused, so young, maybe it’s not the color she thinks it is.” You overhear your father late one Saturday night.
“She has your eyes.” It’s always been said, Yuuta has Mommy’s eyes, beautiful like the clear blue of the ocean, and you have Daddy’s, sharp and all-seeing, as Mommy would say.
There’s an exhale of relief when your brother starts to distance himself from the family, each day growing colder and farther, until he walks out the door with a hushed goodbye and one last kiss to your temple leaving you to think he’d come home.
The thread grows thinner and thinner, finding yourself tugging at it late at night and early in the morning, wondering if Yuuta-nii feels it, wondering if it will bring him home. As the years go by you watch it stretch and stretch, for a few months it’s so thin you’re not even sure it’s there anymore.
Somewhere along the way you stop staring at it forlornly, you push the questions of where he could be or why he hasn’t come back aside. By the time you’ve entered your teens you perfect pretending it doesn’t hurt, that you don’t miss him.
At twenty, fast asleep in your cramped apartment there’s a tug on the string, barely there, waking you for just a second before your eyes flutter shut. Again there’s that tug, and then again, growing stronger and stronger by the second.
“Yuuta-nii.” The name is pulled from your chest in a broken gasp, eyes forcing open as you scramble out of bed, practically landing on your face as you stumble frantically around the room.
His number has been out of service for years, the last time you had heard from him was last year on your birthday in the form of a postcard from some country you had never heard of. It doesn’t stop you from trying to call, chewing on the side of your cheeks as the recorded voice tells you there will be no answer.
With a groan you toss your phone aside, bringing your hands to your face at the sheer irritation starting to replace your exhaustion.
Mommy, why does the red string lead to Yuuta-nii?
Best friends, you’ll always be best friends.
One day I’m gonna marry Rika.
“No.” A shake in your legs has you falling to your knees, the familiar tightness in your chest bringing forth a rage you hadn’t felt in years. “You can’t.”
It’s a whisper, a declaration, a vision of the eyes of a girl from all those years ago who took him away, your brother, your soulmate, the memories eat away at you.
He’s mine, he’s mine.
There’s the old itch of wanting to tear your nails down your arms, to rake your fingers through your hair ailed by the temptation of ripping it out. Just to feel something, to ground you, to distract from the deep pain in your chest.
There’s another tug, the string being pulled tightly towards the door of your room.
“No.” You’re unsure if the admonishment is for Yuuta or yourself, heart aching at the thought of him needing you.
But where was he when you needed him? He’s the one who left, who walked away without a second thought. So you shouldn’t be pulling on clothes at nearly one in the morning, shouldn’t be tucking your phone into your pocket readying yourself to go out into the world in search of a brother who’s long abandoned you.
It’s pitiful really, the way you stare so longingly at the thin scarlet thread tying you to him, following it with heavy steps and a heavier heart.
You know it’s a slim chance of actually finding him, following the thread had never produced any results in the past. You could be walking for days and never find him, the nagging voice in the back of your mind begs you to turn back, chastises your stupidity of even leaving your warm bed.
There’s a sound of gravel being kicked just behind you, your teeth digging into your lip as you try to pass it off as a small animal or a particularly strong gust of wind.
“You’re…?” You practically jump out of your skin, twirling on your heel with your hands raised defensively, a frantic need to run rising in your throat. “Oh, huh, you look nothing alike. How’d ya even find this place?”
The question seems to answer itself as knowing celestial eyes peeking over sunglasses take note of your right hand, tracing along the path of the thread towards what looks like an abandoned shopping center.
“Oh? Oh? He never mentioned that, pft I’ll probably get in trouble but…” He’s faster than you could’ve imagined, the tip of his nose ghosting over yours, frozen in place by his hypnotic gaze, “this is just too good. You’re here for Yuuta, no?”
“No!” You blurt, leaning away and shaking your head at the failed admission “I-I mean, yes. I’m l-looking for Yuuta-”
“Well you shoulda said so earlier, close your eyes.” He sings, only sending you further into a panic. You take a few steps back, readying to turn on your heel and run like hell. There isn’t a chance of even thinking of an exit plan, a hand around your eyes and a darkness overtaking your consciousness in a matter of seconds.
You wake up slumped in a chair, neck aching and mouth dry as you blink away the drowsiness. Your attention is drawn to the stark white of the walls, ears ringing with the sound of a rhythmic beeping when you take notice of the bed before you.
And an unconscious Yuuta lying in it.
“Niichan!” You scramble forward, tripping over your own feet as you land on your knees, gripping at the edge of the hospital bed. Your stomach turns at the dark bags under his eyes, the way he’s only a few shades lighter than the sheets curled around him, the bandages scattered along his body.
A sob breaks from your chest as you muster enough strength to crawl onto the bed, sitting at the edge as you take his hand in yours.
“What did you do,” your voice cracks, moving a hand to cup his jaw tenderly, “where did you go?”
There’s a cut running along his left cheekbone, his lip split and still raw and a nasty bruise forming along the bridge of his nose. It makes your own skin sting, trying not to think what could’ve possibly caused this damage.
Too many times would you be caught in your imagination, wondering what your reunion with him would be.
You imagined it’d be something like him showing up on your doorstep late one evening, you would burst out in anger and tears, hands slamming into his chest as you cursed at him and demanded answers for his absence. He would let you scream, take each scathing comment then draw you close and wipe away your tears, promising that he’ll never leave again.
It wasn’t this, nothing like this, not here in a strange hospital or maybe clinic, with him battered and unconscious only spurring more questions than answers.
“He’ll be fine.” A woman in a lab coat emerges from behind the mint green curtains, the man from earlier standing behind her with a dopey grin and his sunglasses replaced with a blindfold. “He’s a little beat up but he just needs rest.”
“I- who, where?” Voice croaky from your still dry throat, mind reeling from waking up in a strange place with Yuuta tucked in a bed and two strangers who seem all too familiar with him staring at you.
“Does it matter?” The man flicks his hand dismissively. “You’re back with your brother, or perhaps…”
He nods towards the thread resting between you and Yuuta tied securely to your right pinkies.
“You can see it?” He’s kind enough to entertain the question, nodding again as he tilts his head at Yuuta.
“Can he?”
You want to say no, you hope the answer is no.
“Ugh.” Yuuta’s hand twitches in yours, an uncomfortable groan tumbling from dry lips. You lean in, eyes jumping around his face in search of any indicator of too much pain.
He mumbles something, swearing —or perhaps wishing— it sounds something like your name as he stirs slowly.
“Rise and shine sleeping beauty!” The man is hovering over Yuuta, tugging the woman along as he lets out a low whistle. “Took quite the beating huh? Oh well, your efforts are rewarded, look what I found.”
Yuuta blinks, flinching at the light above him. Those familiar ocean eyes come into view, rocking you to your core, tears pricking at your own.
“What?” He shoots up, causing all of you to jump at his sudden movement, his hands gripping at your shoulders. “What are you doing here?”
“We’re going Satoru.” The woman declares, grabbing the man by his ear and past the curtains, offering a kind smile just before making their exit.
“I, I could f-feel you were hurt.” You find it hard to meet his hardened gaze, staring at the bob of his throat and the bandages adorning it.
“You shouldn’t-”
“Don’t make me go.” Your voice cracks, gathering enough courage to meet his eyes, heart stuttering at how it feels like home. To be this close, to have his touch again, you’d be damned if he left, if he sent you away.
He starts to move away, but you chase his touch, throwing your arms around him and burying your face against his chest. His arms go limp by his side, sagging against you, a sigh of what you hope is relief fanning over the top of your head.
“I wanted to be strong for you.” He murmurs, his heartbeat comforting. His hands come up, moving to cup at your face to look you in the eyes. “I needed to protect you.”
“You’re strong enough, please d-don’t leave me behind, I don’t need you to protect me,” tears fall from your eyes, running over his hands, “I need you to be with me.”
You squeeze your eyes shut, hoping your words will resonate, praying that he’d at least consider them.
He whispers your name, once, twice, then over and over again as if he’s a starving man in need of his fill. You feel chapped lips plant themselves against your forehead, a warmth blooming in your chest.
You revel in it, the feeling of completion, of unadulterated bliss.
“Look at me.” He mumbles, complying with the request as you tip your head back. He brushes his lips over your forehead, down the bridge of your nose, pausing at the tip of it, then hovering just over your own.
Best friends, you’ll always be best friends.
You realized long ago that the red string meant more than that, that it was the very reason your parents never searched for Yuuta, that it was a curse damning you and your beloved brother for eternity.
But your parents are across the country, and Rika is nowhere in sight. There’s nothing stopping this, nothing stopping you.
You tilt your chin up just enough to close the distance leaving barely a sliver of space between the two of you. Silently you beg, beg for him to let go, beg for him to choose you.
And so he does, slotting his lips against yours in a kiss that lasts no more than a second, yet it sends sparks through your chest, through your entire being.
“More Yuuta-nii, more.” You manage to pant out, moving your hands to grip at his shoulders.
“I’ll give you everything, anything.” He confesses before pressing his lips to yours again and again and again.
And for the first time in nearly ten years, everything feels right.
