Chapter Text

PART 1 : The One Who Got Away

"Woof" Simba barks. "What's wrong?" He looks towards the wall clock of the hall "oh yeah, its time for yer evening walk. Omi-kun it's time for Simba's walk" Atsumu calls to the empty passage of their apartment
"Yes I know, I was just fetching his belt" hooking the belt in Simba's collar "Let's go love"
"Take care"
"Yes, see you soon"

Atsumu goes in the kitchen to finish washing the dishes. He picks up Simba's bowl for cleaning, a thought surfaces in his mind and Atsumu willingly gets lost in it

Do you remember when we got him?
We were doing our warm up runs for practice that day, outside, on the slopes of the hills- nice change from the ground. That fateful day you decided to join us and we lost you. You ran so fast beating me, beating all of us, we lost sight of you (I was so worried) or maybe you got misdirected to the right place....

cause you always manage to see what we don't. We were searching tirelessly, panicked, for you. You became so important to us, to me. No phones on us- just our voices and calling out to you, calling for you. Loosing you even for a minute was enough for me to loose myself forever - imagine what a full 15 minutes did to me?

....but

"I found her" Bok-kun said. There you were and I breathed in a sigh of relief even when your appearance wasn't radiating the same -I wanted to be mad instead I was just happy to have found you.
Messed up hair, bruises, your tank top partially-unevenly torn and that piece of cloth wrapping up a tiny ever so precious life holding it in your arms, embracing it with your warmth - looking down at it, giving it a comforting smile. Cause you knew that what it needed. You knew.
and I got jealous. Atsumu chuckles at that thought.
cause I knew what that feels like and I wanted to be the only one to have it- your warmth. I ran to you, taking in all of you in my arms- never wanting to let go, glancing a look to that life. It had the same appearance as yours but not your smile. It was curled up-tail covering it's face and shivering. My heart ran out to him too, you know.

"I found her, I found her" Bok-kun went on to inform anyone looking for you, bothered about you.
You knew I was too and so, your hand found my face - comforting me and before I could say anything, before I'd freak out
"I'm fine Tsumu' Hey don't worry, I'm sorry to have gone missing" "I noticed a murder of crows flying, as we were running up the hill, in the woods. Could be any reason why they were gathered but I heard a squeal. Before I knew it, I was just running towards it...there I saw the crows trying to attack this little puppy, Atsumu. This scared life was hiding under a dense bush which had the crows finding it hard to get through to -to get to It. I had to help, how could have I not?" "I shooed away the crows with all my might, they tried to attack me too but ah! I'm strong hit em with a stick they flew right off. Argh, I was so mad at them, I threw that stick as they were flying away and managed to hit one of them" you smirk and laugh and I wanted to be angry at ya but I was still just relieved to have found you.

"the bush was really thick, huh? you did good little guy- you were smart to hide under that bush" ya say to that tiny soul while rocking him in your arms. "you were so brave tiny one I got a few scratches trying to get you out of it and you have some too, we need to get you to a vet"

"Hey where were you? We were worried sick!" Meian-san scolds ya
"I;m sorry for that, but, please before that we need to take it to the vet. It doesn't seem to be hurt much but its scared to death and I'd like to get the vet to take a look at him"
"You're hurt too" I say- I was mad now you seemed more worried about the tiny, than you, than me
"Ooh come on Tsumu' they're just a few scratches, I'll be fine"
"Fine we"ll take it to the vet" Bok-kun & Shouyou-kun offered. Taking the tiny carefully from your hands and how carefully you handed it over-
"Thank you so so much"
"Oi, let's take care of yer wounds now"
"Would you relax now, stop worrying already!" I could tell, you sounded annoyed now. How from one moment to being worried so much to getting annoyed at me, how'd ya do that- I never knew. I would never know"
"It was just what? 15 min? You need to relax your nerves for practice Tsumu'. I'm here now"

....but you weren't

"Hey Hey Hey! There you go, this little one is all fine. The doc gave him some medicine and meat and veggies and water...
...and Bokuto-san was drooling over them" Hinata finishes
"But it looked tasty!! Anyway this brave one is all good, aren't you?" a very faint woof was heard."There see, you're gonna be my side kick tiny and we're gonna save the world"
"HUH? WHAT WAS THAT NOW?" you sounded mad, really mad. Everyone could tell, they all flinched even Omi-k...

Atsumu realizes that there are no longer any dishes in the sink that needed to be cleaned so, he proceeds to wipe the washed ones. Again, willingly loosing and continuing-

"Bokuto-san! It's going to be living with me- with us. Tsumu' are I gonna adopt him"
"Ehhh no fair"
"I found him, I rescued him"
"But I want a side kick"
"Oi, she gets to keep it. She found it" Sakusa annoyed desperately wanting to end the silly argument and get back to practice.
"Finders keepers Bokuto-san, besides I don't think Aka-" Hinata's interrupted
you giggle "Nothing like that, I just already love this guy, ended up imprinting on it and I want it- I fought for him, I want to love him. So, I'm gonna fight anybody who comes my way for him"
There was once a part of me that wished that you'd do the same for me

So, Tsumu' we're keeping him. Hey! little one you're coming home with me-with us! I'm going to love you so much" muah muah muah you go rubbing him at the side of your cheek with starry eyes
"Huh? Don't I getcha' say in all of this?"
"No you don't. hehe." you say teasingly, rubbing our noses together
"Look at him baby! He's so cute. He needs a home, he needs love, he needs us";

....but you weren't there

......You were the one who got away......

Atsumu has now finished with his chores waiting for Sakusa to return so that they can to their own walk in the silence of the night. He has a big smile on his face, he can't wait.

Sakusa is walking Simba on their usual route. The different colors emitting via neon & LED sign boards of various shops are lighting up their path - "It's a beautiful day indeed", Sakusa, while patting the left side pocket of his coat, says out to himself. "Huh, what?" His gaze had wandered away and with the sudden stop of moment, it returned, and he saw Simba staring with drool through the window of a froyo shop.
"So, you want some yum-cream? You know you just had a heavy meal and a treat after that" Sakusa says while petting him.
Simba staring at Sakusa with the most adorable puppy-eyes, Sakusa has yet encountered - and that did the trick! Sakusa storms into the shop and gets a plain flavored "yum-cream" -Simba's favorite. "Don't tell your daddy". Simba's just busy licking away his treat to oblivion. "Pfft...how did I come to love you so much? Baiting me with those eyes."
"It wasn't like this always you know.....

"Omi-san, why are you so cold to Simba?"
"Because I don't like It" Sakusa blurting out, like a reflex
"and why not?"
"Have you seen it? Tch, Its just another energetic chaos like those other two, the only difference between them -It has fur"
"Eh? but Bokuto-san and Shou-chan don't walk on four legs-"
"They can if they wanted to and I, for once, have even encountered it, without wearing shoes just like that hairy being, EW-"
"Omi-san!"
"I'm sorry, that's not the only difference -Bokuto and Hinata don't lick away your face as soon as you meet them"
"Hahaha Omi-san that's the way he shows his love, you know? This fuzzy being knows nothing but to love - unconditionally! who else and what else can love you so much at just first sight? Can show such affection to a complete stranger?"
"I don't care. Keep It away from me"

Strange. They say hearing the joyous sound of someone you consider special, makes one feel something extraordinary within. Your laugh, I hoped would do it. I waited for it but Strange. I felt nothing out of the ordinary.

"WOOF!" "Grrrr....WOOF! WOOF! WOOF!"
"Huh? what now?" Simba's barking at a stray cat out aloud, he fights Sakusa's grip, pulling him, wanting to chase the stray.
"WAIT! Simba don't run....

"don't run away omi-san
"....."
"Answer me? Why are you avoiding me Atsumu and Simba...Simba I understand but, why me and Atsumu? Isn't he your teammate? You're being really cold than usual to him even I see that"
Ah! there. Your talent of reading people well. Annoying. Maybe that is why, you knew me so well.....
"Nothing out of the ordinary happened between you and him or you and me. Tsumu' tells me everything so I don't get the why? I have ran all simulations even Sakusa Kiyoomi 101 cautions in my mind and all I can think of is that you like-
"I like you"

Strange. They say that when you show your vulnerability, you hesitate for a moment. They say you feel your heart experiences an irregularity by a skip of a beat when the words of affection come out of your mouth. They say your heart experiences a sudden rush of regularity, where you hear nothing but its beats in the anticipation of an answer. Strange how I didn't feel any of those.

PART 2 : The One Who Brought Us Together.

Sakusa managed to get his command over Simba back. They were now strolling, in a quite place surrounded by the comany of Sakura trees who were resting from their bloom. It was peaceful and Sakusa for a moment wanted to lay there instead he chose to reminiscence.

You were quite a handful. All over the place, on the court, off the court with him. Participating in the rowdy duo's shenanigans. Irritating. I didn't know I'd be meeting you when I joined. Like the members weren't enough I had to deal with you. yet somehow you seemed bearable than anyone. You were in our pack (long before I joined) like you always belonged there. Like I was meant to find you. Maybe that is why it was easy to tell you cause you made things easy. Even having a Sakusa Kiyoomi 101 framed in your mind. I a man of few words and you read me like a book. You perused me.

....you're there

"So, now you know, why I have been avoiding you. Knowing you're with him and no less of an irk than him. I had to put it out there, for it to stop. I cant leave things in between, not like this. I have to finish...
"...what you start, right? But you didn't let me finish, Omi-san" you responded the same way I did, calmly.
"You don't like me. You like Atsumu"

Atsumu. I hadn't familiarized myself with name which everyone's tongue used. The variations of the name, they used, the name you used. He was Miya to me and yet I felt something.....
Feelings for someone, is something I'd believe I would never have. There was no need for it, I had no need of it. I, who prepares, is careful, heeds to everything, had not prepared for something so unexpected, so needless. Though, that's the thing right? Nobody does. Feelings, the internal intangible rush of chemicals, we are left to deal with ourselves. I only know of all this, I only felt something

....cause you were there

Huh? I asked. Confused, you said.
"I am not who you feel this way about Omi-san. Maybe not Atsumu but definitely not me."
"Oi, What are you saying? It. Is. You. You care about me, you look after me, you know me so well-"
"Yes, but do you?"
"......", all those internal questioning, all those wonders had lead me here (finally) and for once, maybe for the first time in my life, instead of always opting to be mum- I was actually speechless.
"It's okay, Omi-san. If you're wondering how I know, it's cause you don't look at me the way, the way I look at Atsumu."
"It is in your eyes. It has always been your eyes, Omi-san. Even though they are dark and deep they make you transparent as water to see everything under."
I choose to remain in the same state of voiceless, perceiving every word you say. Just those words going right from my ear to my soul and nothing else.
"Well your eyes are in fact, the most exposed part of your body that and I have noticed how you look at them" your head turns looking at the direction of those 'beautiful souls'
"...and there's a faint believe that maybe, it's your 'preference' - which is not ordinary but extraordinary"
"Omi-san perhaps not today but maybe someday you'll know, I'm right. Cause Omi-san...
You then proceed to tell me that becomes the very foundation of my self and unknowingly it become my nucleus. I had a life-like example of same right in front of my eyes, 'those two beautiful souls' maybe you did know what you were saying. So, thank God for that.

....you were there

......You were the one who brought us together......

By the time I figured out my true self.... you disappeared. That's also when that happened. Just like you said.
There he was shattered (what? what is this?), limbless (why? stop), wailing (just stop!) and I ran to further ends my legs were taking me. I could stop but my legs wouldn't. Finally out of breath, heavily gasping in air like the only thing I knew to do. Somewhere, leaning against the wall, crumbling against it on the floor, both my palms blocking the light in my eyes, "SHIT! Shit! Shit" a loud expectorate.
Not caring about where I am - the dirty wall, the filthy floor that's when I knew for sure- you were right.

That sight tangled me up in knots and I chose to remain like that. I chose to make my personal space even more personal - to hide, especially from him. Though I noticed him. Everyday. "Space", Meian-san said to us. For him? or for all of us?
I wouldn't care I was in a space of my own, I had just felt the sharpest bow strike me, maybe cupid's- couldn't tell, not just yet. I had my own griefs to deal with - that agonizing sight and loosing you. You hurt everyone.

Sakusa now looking at his wrist watch, "Oh an hour is almost up. Yeah I think, we could stay a while longer, don't think your daddy would mind much", cupping Simba's face gently, he says to him. Atsumu definitely didnt mind. He kept himself busy playing Pro-Soccer with Osamu, online. His smile from earlier had grown into a grin. This was the seventh match and Atsumu had already won five times. It was a good day indeed.

"Don't fight your feelings, don't deny them either. Its not fair to the other person more importantly its not fair to you. These feelings are there for only one reason - to feel. Believe me embracing them requires less struggle than the internal clash, Omi-san"
"Ok. It has finally happened. That idiot's rub off on you. You're delusional now. It may be contagious. Don't come within 50 meters of me."
"Nah, that comes from experience you know" shiny eyes, and that curve on your face stating it to be true.

It took me a long time to open up and accept my preference and it took even longer to accept that the 'which one' was Miya Atsumu. I fought with my preference, I denied my feelings for him, but the moment I realized- that I loved him that it was indeed cupid's bow that struck, I embraced them. Love found me, just like you said. You were long gone now. It was my turn to love him- to love, my first love.

PART 3 : The One Who Is Here.

Hey ya know, sometimes ya talked in big words a lot. Hahaha! totally not gonna lie, I didn't even understand a quarter of you said. Ya threw around a lot of that physilophical stuff amd I thought I could figure it out, I wanted to so, I tried. Actually, I thought I had it all figured out. Yer, me, our live, our love, volleyball. But you simply can't figure out everything and all at once. It's complicated.
Pfft, doesn't even work in volleyball. All you need is time and patience which, we didn't have.
So, when the next came along, when love found me again, I gave in to work hard. Harder.

I had it all figured out but you weren't there. There was someone else and I'm glad it was him. Simba made me the feel the warmth I needed (exactly when I needed), what you always talked. Always merry, cheering everyone up cause that's all he could do right...after you left? I gradually let myself open up to him. Wasn't easy. Never is. Not for me. At that moment, it seemed right. It felt good. Whenever he ran towards me with his tail wagging and with such joy, I always thought "why to me? why to someone who's so cold to you?" and I bet he thought "why not you?" and I gave in to another creature who always have their tongue out. Gross.

Time is a funny concept, ain't it? People take it for granted easily and when out of the blue, they're left with a little less of it they panic- wanting it more. Wishing they could do, cherish what they could have, hoping to have said right words, hoping they did right. Some people find out the answer, some don't and I would never. It's okay but, it doesn't matter now,
"Your first love doesn't have to be your last love".
Our love had me in a trance. It was dreamlike and I just want it to be dreams now cause when reality struck I had given up on one thing that sustains this world. However-
You deserve to be loved, Atsumu!!
you deserve to be loved, BY ME....
-Sakusa Kiyoomi

Do you know how it happened?Strange. They say- actually, it was science all along and there's a theory in physics which states that some specific sounds increase the rate of your heartbeat.
There he was, standing tall, tears forming in the corner of his eyes, collapsing....into a roaring,boastful, most beautifu laughter. His most faithful, genuine laugh, (2 years without you, 2 years after you) at something Hinata said. So, when my frown turned upside-down, when it became so honest that it'd hurt my face, when my heart left my chest and ran out to him, I didn't realize. It was all in a snap when the bow struck.So, for me, that specific sound was his laugh. That's how I knew 'I love him'.
"Not everyone is lucky is enough to call their first love their last love"
Just like always , I got lucky. Lucky being here, lucky meeting you, lucky-loving him. So, I'm gonna see this through till the end, knowing that I could be done anytime, I'll give my 120% at every moment- for the satisfaction. Since, you don't have to do it alone
Thanks for loving me, Omi
I'm not gonna disappoint ya, ya know, I gotcha'.
You need to know. We're gonna work this out TOGETHER.
-Miya Atsumu

Atsumu and Sakusa have left their home, managing to put restless Simba somehow, to rest, in bed. It's the penultimate hour before the clock strikes a new day and the couple are walking hand in hand towards their common place of meditation for each other. Atsumu's free hand absent-mindedly wanders to the left pocket of his jacket and Sakusa's- consciously, to the left side of his coat. Moon's light seemed faint compared to the gleaming aura of the couple. It really had been a great day and all they wanted to was to end the night like that.

Hey ya, I just wanna finish this and say, Thank you. Thank you for being my 'the one who got away'. That just made me appreciate and love him more- to hang on to him tighter. Thank you for taking that title away from me forever cause,
My yesterday is gone :
Hey I'm fine, Tsumu
What I do today, is all that matters :
"I'm home, Tsumu' "
So, I'm gonna go ahead and grab "the one who's here"

All I want to say to you is now, lucky or not wouldn't have been possible had you not been there. Your presence brought me closer to Atsumu and your abscence to Simba. So, Thank You for being 'the one who brought us together'
I'm going to see this through till the end and hang on to "the one who is here"

With less than one hand distance between them, hands digging out something of their left pockets, the words that follow will be with them forever, will be there forever....
"Kiyoomi"
"Atsumu"
"Will you marry me?"
"Will you marry me?"
.......I'm going to be with "The One"

Chapter Text

PART 4 : Q&A

Before we begin, how about some light on the background of the character and on the timeline?
She's tall, I'm thinking 5'9, she's got brown hair and deep blue- ocean like eyes. She's a young CEO of her own fashion company and also, one of the main sponsors of the MSBY, how else do you explain the half n half claw marks from the jersey to the boys's shorts? That's also, how she meets Atsumu and they share the same dynamic and tension as SakuAtsu and they hit it off. As a couple, people often said that they are like Sun setting in the ocean as Atsumu's eyes are golden and I'm comparing them to the sun. (Damn! That's good!I should have used it in the main story. Nevertheless, this is also very much part of the story)
She's a people's person. Her living is basically based on her reading latest fashion trends, fashion choices- people's behaviour and she's good at what she does just like Atsumu. Clothes are very much capable to reflect people's mood so, in short she reads people well. She's a exceptional at communication. All qualities for her being a CEO. She's a badass too- she's into kick-boxing and doesn't take trash from anyone. Especially, when it comes to her ownself or her work. If, Atsumu would attack her personally (which he would cause he is who is) she'll shut him up with the perfect comeback. She immediately gets close to everyone and forms strong relationships with them with her bright and spirited nature. It's fairly easy to get open with her and that's how she ends up meaning so much to everyone in the team.

Timeline is...she and Atsumu meet in the year 2016 i.e. when Atsumu was 21 and they're both of the same age. Their relationship lasted 3 years and I believe Sakusa joined in 2018? there isn't official clarity on when Sakusa joined MSBY, so I'm gonna go with this.
After their relationship ends, it takes 2 years for Atsumu to recover
[See Part 3, Sakusa's POV - His most faithful, genuine laugh, (2 years without you, 2 years after you) at something Hinata said.]
Meanwhile, Sakusa is fighting & denying and finally coming to terms with his feelings for Atsumu.
In the present timeline, the year is 2025 Atsumu is 30 years old and Sakusa is 29. They have been in relationship for nearly 4 years before proposing.

What is the final word on the fate of Character? What is the official status on her's and Atsumu's relationship?
That's up you to decide. Yes, you, my readers. You can choose one of the following scenarios I present to you :-

The character and Atsumu broke up and it was an ugly one. A real really bad one that had the character to never return. Ever. She just blatantly walked out, nothing on her - just the clothes she was wearing, her phone & purse and disappearing, from everyone and everything that had to do with Atsumu. Just like that. Literally.
No words. No news. Completely becoming alien
I mean, understand, it was excruciating, cause it had her leaving Simba behind! Wasn't easy for her too, you know but you gotta what you gotta do and people can take extreme steps when in pain. The pain was equally numbing for both but, you know, maybe she thought too-that Atsumu was her "The One"

She dies, the common notion. A sudden death- by accident or a natural cause, one day. Just like that. Leaving things unsaid, questions unanswered and same goes for the above scenario. Atsumu or anyone have no contact with her in either cases.
Death is untimely that's the only thing you can rely on it for.

So, if she's just a flight away or far away where it isn't possible to reach even with a spaceship- She's gone. For Good.

Why and what's Akaashi doing in all this? Why is he the one credited with quotes in Part 3?
Ah! This is my favorite one! Well, many of you may have guessed BokuAka in this fic and yes, that's very much true. When in Part 2- Sakusa mentions, "2 beautiful souls" he's referring to BokuAka who at that time are officially boyfriends. Sakusa doesn't consider them to be "beautiful souls" at that time but eventually he realizes BokuAka's power (#BokuAkaSupermacy) and refers to them as beautiful souls (cause they be soulmates)
In the present timeline Bokuaka are married and have a son! Moreover, Akaashi's writing a book titled "We Are The Protagonists Of The World" whichhhhhh is for the LGBTQ community! He writes about homosexual relationships (his own and SakuAtsu's), love, the challenges, the pain, maybe even a few pages on parenting?
So, when you see those quotes in Part 3 it's actually what he wrote for SakuAtsu!

Bonus : For his "attempt at humor", Akaashi even throws in the quote- "Love is like Oatmeal. It sustains you." in the book. (Did you get that reference? Comment if you did *wink wink*)
The book goes on to became a top best seller and it's endearing. Also, has a very positive impact on all mankind. Akaashi's writing is realistic and relatable by LGBTQ and Straights alike. Like Furudate-sensei! To summarize-
Furudate's writing. Impact like Yuri!!! on Ice and Success like Fifty Shades of Grey.
(Not indicating some other meaning. comparisons are just for better understanding)

Why does Akaashi, in the end, quote Character's quote in the summary?
For BokuAka the character acts as a catalyst. I think for BokuAka it's the classic "everyone sees but them" and the character is smart here, so she uses that quote (in the summary of the previous chapter) to give a nudge to Akaashi to be with Bokuto. In this story, I see:-
Akaashi, a fool to deny his feelings, and
Bokuto, a fool to not realize his feelings
So, the character is clever in choosing her fool and targets Akaashi, who of course understands words better and process those words and his feelings better. And yes, Akaashi confesses first and Bokuto immediately realizes and goes, "OOOOO!! Now, that you say it!! AKAASHI! I LOVE YOU TOO. I REALIZED THAT JUST NOW AKAASHI! DID YOU TOO AKAASHI? HUH AKAASHI?! YOU DID TOO AKAASHI RIGHT?! AKAAAAAAAAAAASHI!!"

The character does the same thing with Sakusa, she says the same quote to him in Part 2 [You then proceed to tell me that becomes the very foundation of myself and unknowingly it become my nucleus. I had a life-like example of same right in front of my eyes, 'those two beautiful souls' maybe you did know what you were saying. So, thank God for that.]
She tells him the quote here again picking a smart target and the life-like example are BokuAka. Though here, her implication is for Sakusa is to make him realize that he is gay instead of making SakuAtsu happen. She uses Atsumu as a reference to make Sakusa known to his choice of gender. (She. Was. Not. Sabotaging. Her. Own. Relationship.) Please, their relationship lasted for one more year after that while Sakusa was figuring himself out during this period.

The quote becomes really important to both Akaashi and Sakusa, becoming their nucleus and hence, Akaashi chooses to use that quote in his book *peace sign*

How does Atsumu move on after the relationship ends?
I don't really think he would really bother about what went wrong cause the break up would be mutual and death untimely rather, the aching he's going through makes him leech onto-what could have been?
Atsumu was shattered after, but not destroyed. That's not who he is. He's dealing with a loss yes, but doesn't give up. He takes a couple days off but he still takes care of his nails and plays volleyball. A habit deep situated within him which he can't let go off. Though he's just through motions. He's still a 'monster' and uses all that cocktail of emotions-puts it into his game and excels. Though he shuts everyone out, talks only when necessary in practice, in games but nothing else other then that.
Well you know that "The other twin will always be there" so, yeah, Osamu is there. It's bad and Osamu definitely realizes the gravity of the situation and he goes-
"You're always too full of yourself how can you agree to lose yourself like that - completely?"
"No! absolutely the hell not! I refuse to accept you as my Twin if you're like that... Give me back my annoying egotistical Twin!"
His role is to make Atsumu known to self-love again. The original character was his first love so, he went all out and love can be somewhere where you can end up loosing yourself especially self love there needs to a balance which is difficult but, you learn with time. For him it was all "rainbows and unicorns" he needed to realize that love is roses with thorns.
[See Part 3 - Love is not all rainbows and unicorns.
It is roses with thorns. -A.K.]

and Osamu's efforts get validated aka he knows Atsumu's recovered cause...
"@bettermiya : Guess who's still the hotter one?"
It's a mirror selfie. Atsumu has posted a shirtless picture of himself just in his boxers, on Instagram. Water is dripping from his wet hair on to his toned body. The sun rays reflecting off the mirror making the water look- liquid gold just like the color of his eyes

When Osamu sees that post...
"Yeah he's back to himself. Annoying brat." he has a very big genuine proud smile on his face cause he can feel it that Atsumu is okay with his twin connection

(Some extra thing I wanna add here is that Sakusa wasn't the rebound guy. The timeline makes it very clear but Atsumu did not depend on Sakusa to recover neither Sakusa was there to do that. In fact he had distanced himself from Atsumu when he found out that he liked him.
Sakusa, I really don't think would ever be a consolation prize, that's not what I make from his character.)

How and when does Atsumu falls for Sakusa?
Atsumu is still not open to the idea of love but he's back to his mean self with his smirk plastered, after over a year. Although that's the thing you know, "you don't seek out to love it seeks out to you"
His straightforward and outspoken teammate who lived to only annoy him (Atsumu's thoughts) had suddenly started warming up to his dog and "Wow Omi-kun is capable of loving something/someone other than Mr. Clean"
When he tries to get on Sakusa's nerves he just doesn't response with the same blunt annoying attitude...
Atsumu starts noticing the change in his behavior and is utterly muddled. "Why why why" and in the process of figuring out the why-
"Here's the game folks the one we've all been waiting for - EJP vs MSBY"
"Yeah! Both the teams have got one on one going against their former allies in the High School"
"This is a contest to look really forward too"

"A perfect pass by Hinata... who's Miya going to use now?"
"Hmm.. I know what yer all thinking but here! Omi-kun, I'll give ya the easiest set. So, throw the nastiest spike at Komori-kun... Huh? What? What just happened right now? Omi-kun jumped to spike and...those curls, those perfectly placed two, darker than the night stars- shinning bright with his sweat, that form, his nasty hands. What a view. My heart? It lost its rhythm right now. Oh no! This is a familiar feeling."
Cupid's bow had struck Atsumu now amidst a match.
Atsumu realized it was love and Omi-kun?! Are yer kiddin' me? He goes on to hide his feeling until he drunkenly confess to Sakusa who upon hearing this doesn't hold back and immediately responds with affirmation. Once he knew Atsumu felt the same way too, he fought for him and he said the best thing ever (God! I love this one) -
[See Part 3 Atsumu's POV -
You deserve to be loved, Atsumu!!
you deserve to be loved, BY ME....
-Sakusa Kiyoomi]]

Why is the couple remembering the character on this articular day?
I think most of you got the idea from the story why...cause they're gonna propose. They are remembering her with their respective titles "the one who got away" "the one who brought us together" and thanking her because that's what led them to take this decision of being together forever even saying their goodbyes to her.
One thing I wanna point out that Atsumu never got closure so he chooses to think that she's fine whether she's amongst the breathing ones or amongst those who are not...."
[See Part 3 Atsumu's POV-
"My yesterday is gone :
Hey I'm fine, Tsumu
What I do today, is all that matters :
"I'm home, Tsumu' "]
(Today being Sakusa who says "I'm home")

Quotes here, quotes there, quotes everywhere. EXPLAIN!
(kyaaaaa you all sound like my alter-ego hahaha) Here we go though from the very first one-
"Love, it's not what you seek out for, it seeks out to you. So, how does it matter whom, what or which 'one' we love? Its sunshine for some and rainbow for some.
You'll fall for it, in the end, like a shooting star. Go ahead, make a wish... cause you're only human."

In this the first line is pretty self-explanatory- You don't find love it finds you.
The second - How does it matter which one you love? What is your preference. Be yourself be with whoever you want to be in the end it is love after all.
The third one- "Sunshine" is being referred to Atsumu as he has golden eyes and I compare him with sun in this fic
"Rainbow" is Sakusa cause he's Gay and of course a call out to LGBTQ community.
Fourth line - "Star" is Akaashi. Remember when he first sees Bokuto and goes "He is a star". So-
Go ahead, make a wish... cause you're only human
In conclusion, the character pushes and tells people that "Every time someone steps up and says who they are, the world becomes a better, more interesting place." (yes that's again a reference to B99 and this is just too good to be left out especially for this fic)

"Feelings are complicated. The more you untangle them, the more tangled they get...
and even if you manage to untangle them, the moment you do that,
there's a new one waiting for you. That's Love."
This when Akaashi wrote this for SakuAtsu in his book was to indicate how it was a tangled up journey for the couple before they became a couple to figure out their feelings. Atsumu having to deal with the aftermath of the relationship with the character and his feelings for Sakusa.
For Sakusa to figure himself out for instance, When he sees Bokuto and Akaashi ding dongs go in his mind and he comes to the reality that he wants that with someone. That someone being of the same gender only. When he realizes that he starts on his journey. He's the quite kind he'd do it on his own mostly, he'd take help and discuss about it with Komori and yes the character! He was close to her opened a bit easily to her than others. After that, when he had untangled one knot, realizing he was indeed Gay. he had to deal with his feelings for Atsumu (another knot waiting for him) . Love is not perfect and Sakusa likes to be prepared for everything but you cannot with love. No one can.

"How about we uncomplicate love, today. Only today. Just for today.
Let's be prepared for once, let's be careful for once, let's be gay for once, let's win with love-for once" This second last quote, is a contrast to the above just discussed one. The previous one above says "complicate" and here we uncomplicate them cause we are concluding the story.
Today is indicating Atsumu's philosophy of "What will you do today."
Prepared is for Sakusa who realized that you can't be prepared in love but just for once let's be
Gay means happy too, you know? Here it is a play on both, happy and homosexuality.
This one is to summarize how the couple wants their proposal to go perfect just this time- uncomplicated and being prepared then lets go and "win with love" (:D)
(Love is not all rainbows and unicorns. It is roses with thorns. I have explained in the "how Atsumu moves on" question above)