[Masterpost of growing up!hidekane headcanons]
Hide's calligraphy in third grade used to be a messy scrawl Kaneki always reprimanded him for, so Hide always used it as an excuse not to take notes and just use Kaneki's because they were neat and thorough. Kaneki would blush and only give his consent when Hide claimed he couldn't make sense of his own.
Hide's always had an excellent memory and has never felt the need to really take notes, but Kaneki's bullies didn't need to know that.
When they went through puberty, Kaneki's voice was the first to change. Hide would affectionately make fun of the moments Ken would still let out high-pitched sounds just to mess with him, but would abruptly stop when his own voice started to change.
Hide always told Kaneki to just bring over a bag with some clothes and basic necessities since he often ended up staying the night or even showed up unannounced when things with his aunt got bad. Kaneki always refused because he didn't want it to become a habit and felt like he was burdening Hide.
The first thing Hide then bought was a toothbrush. The second, a pajamas that fitted Kaneki, because his were too wide on the shoulders and Ken was always cold even without unnecessary loose fabric. A lot followed, one at a time so he wouldn't pick up on it. Kaneki never noticed.
One year they risked being placed in different sections because Kaneki's grades dropped after his aunt made him do tons of housework as a punishment for scoring a better result than her son in school tests.
Kaneki only told Hide this after he worked hard to have them go back to normal. Hide was his motivation.
Kaneki is really good at drawing but he never seriously tried to improve despite Hide's claims that you don't even need to pull a Picasso to make a small fortune, 'Neki!
Hide snores like a truck. Kaneki usually shushes him by pinching his nose for ten seconds and giving him a dirty look as Hide proceeds to sleep as if nothing happened. It always works.
Kaneki once drew Hide for an assignment them both had to do. Hide hung up the drawing on his wall and left it there for years.
He only put it down after Kaneki claimed he would make him another one. He never did and always dodged Hide's questions as to when will you draw it eh Kaaaa-neeee-kiiiiiii? My wall is lonely!
Hide hung it back on after Kaneki left him. He needed a reminder that Kaneki still loved him.
Hide would sometimes guilt trip Kaneki into watching anime with him after long afternoons spent dozing off on his shoulder in a bookstore.
Kaneki wouldn't admit it, but he quite liked Evangelion. He secretly bought the manga afterwards.
Kaneki once forgot a book at Hide's, Hide didn't notice and Kaneki despaired because he couldn't find it. Hide helped him turning his apartment upside down in order to find it. Then that evening he felt like a moron as he flopped down face-first on his couch and felt a solid thickness under a pillow.
After that one time Kaneki stopped eating for lunches because his aunt kept 'forgetting' to give him the money, Hide's mom began to stuff Hide's bentos with extra food so that they could share.
Hide's hands are really delicate and feminine. Kaneki has a fascination with them, and he once spent an evening sketching them without noticing they were Hide's until he reached the fourth page.
Kaneki thinks Hide is a touchy-freely kind of guy but he never noticed he's not at all this open with other people.
Hide abolished his concept of personal space around Kaneki when he first noticed he gets lonely a lot.
Hide never told him, but he hated Kaneki's mom.
The only ever time Hide wore black was at Kaneki's mom's funeral. He hated it too.
Hide's loud and frankly ridiculous cheerful persona is an act meant for Kaneki and Kaneki alone. He's much more reserved and logical around other people.
Kaneki always wondered what Hide meant when he called him bro. Being an only child he can't understand brotherly bonds, but he supposes the warmth in his chest he feels every time he's with Hide must be him considering Hide a brother.
Hide's hair is not dyed. But his facial hair would still be brown whenever he lets them grow, much to his chagrin.
Kaneki's belly is really soft and comfortable and sometimes Hide would use it as a pillow when Kaneki chooses books over him.
Hide's spiky hair is not soft at all and Kaneki is really ticklish on his stomach, but he thinks he's managed to keep it a secret from Hide. He doesn't want for him to stop using him as a pillow after all.
Sometimes Kaneki is so entranced in his reading sessions he doesn't even mind Hide's hardcore snoring a foot away from him. Hide always teases him for it.
Hide likes shoujo mangas and cheesy love songs. Kaneki calls him a lonely housewife. Hide doesn't protest.
After Kaneki's mom died, Hide made him a playlist and lent him his mp3 and headphones to listen to the music whenever the silence became too overwhelming.
Kaneki never gave them back. Hide never asked for them.
Hide had wondered more than once if he should call child welfare on Kaneki's family. Then he would see his reddened eyes and realize Kaneki would consider it betrayal, because despite everything, they're still family to him.
Hide never feels as powerless as he does every time he sees tears in his best friend's eyes. Kaneki picks up on it and starts hiding it. He doesn't want to ruin his best friend's beautiful smile.
Hide then made it a personal habit to smile all the brighter when Ken tries to hide his sadness, and tickle him till new tears appear in his eyes for a different reason. He always picks Kaneki's belly.
After that time Kaneki muttered "brother" in his sleep as he scooted closer to him on the bed they were sharing, Hide understood just how much he meant to him, to be entrusted with his heart like so many already who had wronged him in the past. Pulling him close with an arm was his promise back.
On valentine's day, Hide would always leave the homemade chocolates he prepared on Kaneki's desk. Kaneki would come to know it was him when one year Hide still had a smudge of homemade chocolate on his nose from the day before spent baking them.
Hide maybe meant it as a symbol to something more than admiration.
Kaneki made sure to pay him back a month later with years-worth of chocolates. Hide's chest felt so warm despite the innocence of the gesture that he didn't mind the cavities he got from eating them all.
Hide would gladly spend his whole life being Kaneki's best friend. He doesn't wish for anything more.
Except one day Kaneki leaves him and Hide wonders why it wasn't enough for him too. Why he wasn't enough.
Hide was a huge Hannibal Lecter fan but after Kaneki's torture he isn't so sure he can quite stomach splatter anymore.
All the mails and texts he sent Kaneki were mostly a reminder to himself not to give up. Not to lose hope. Kaneki already saw them, so he couldn't back out now that he was waiting for him, right?
Hide had never wanted to give up anyway. He just needed the excuse. He really missed talking to Kaneki.
Kaneki never actually read Hide's messages. But he always kept his phone charged and with the sound on. It was his reminder that Hide was alive and safe and that he was doing the right thing. Because he was doing the right thing, wasn't he?
Sometimes in Kaneki's dreams there would be his mom. And then her face would morph in his own with blackened schleras, and he would wake up screaming and wishing he still had Hide's headphones with him.
Some nights he cries so much he feels like the whole world is crushing on him and his finger would hover over the call button next to Hide's name just to remind himself that he would stay human and not become a monster until he keeps denying himself that call.
After Hide showed up at Takatsuki Sen's book signing he would trace his fingers on the "Kaneki Ken" written on the first page, look around with a sad expression for a head of white hair, and wonder why his instincts had failed him.
The thing Hide missed the most about Kaneki was his voice and the way it would rise and drop with passion whenever he read something for him.
Hide would sometimes try to fall asleep reading Kaneki's books he still kept home after Kaneki left. They were too dark and negative for him and he curses the fact he never tried to read them when Kaneki was still home.
So that he would just get it sooner and stop him from his self destructive path.
When he joins the CCG he wonders if one day he'll just go to work to find out that they killed him in action.
Late at night, Hide would sometimes still think that maybe Kaneki is safer with his friends out there than he will probably ever be with him. He already failed to protect him once. Why is Hide trusting the CCG, anyway, other than despair?
When he sees him in that sewers tunnel, Hide thinks that Kaneki was right for not trusting him with his happiness. He's going to betray him and he feels sick. But he'd gladly have Kaneki live a lie and forget than be righteous and die. Hide knows he's selfish, but he can't help it.
When Kaneki sees Hide in the sewers, his mind closes up. This has happened before. Hide can’t be there. Hide has to go, he can’t be there can’t be there this already happened and he is a monster because he let it happen again. And Hide is just smiling like nothing happened, like he can’t see the beast in his eye, and Kaneki just wants to cry.
Hide hopes with all his might that Yoshitoki will keep his promise, because he can't deal with the impossible weight of his best friend's disposal on top of the crushing guilt he already feels for not being able to make him smile that one last time.
Hide had felt silly when he'd wondered with reddened eyes if Kaneki was still ticklish on his belly even after he'd put on all those muscles. The tubes and machines Ken is attached to in his hospital bed prevented him from trying to find out.
Kaneki had wondered more than once who could possibly be the person holding his hand when they thought he was asleep on his hospital bed. They always sneaked in at night and stayed until sunrise, never saying a word. The nurses never found out so he never asked. He wished he could see the stranger's face. He felt as though it was important.
It becomes a routine after a few days and Kaneki starts to become acquainted with the stranger's prolonged silences. It feels like there should be words there, but they can't bring themselves to say them. He feels like that's a strain that shouldn't be there. He wants to ask them a lot of things, but then he always gets awful migraines that leave him winded and gasping for air.
The stranger holds his hand tighter those times. The familiarity and the comfort of that petite hand makes his chest scream in agony and Kaneki wants so desperately to cry, but he doesn't know why.
Then one day they abruptly stop their visits and Haise starts to forget about them.
When they tell Haise he was a CCG investigator who got hospitalized after a run in with a ghoul, he wonders why he chose that kind of life. He doesn't think of himself as the avenger type. Then he looks at the empty chair next to his bed and wonders how great of a family must have been the one he lost.
When Hide sends him that book, he doesn't know what he's wishing for. He's sworn to never tell him a thing about his past. Maybe he just wants to warn him. Maybe he just wish that's what Haise wants, too. Maybe Hide just wants to be forgiven. He can't be sure. It feels like it shouldn't be his choice.
Sometimes Haise would catch Shirazu and Saiko swearing at manga characters or Urie singing under his breath and he would feel a strange melancholy creep up on him at the sheer familiarity of something so trivial.
Hide gets so lonely and he hates it. He hates it that some days he can't just feel like smiling anymore. So one day he goes to a pet shop and buys a kitten. Its fur is as white as the snow and he curses when he realizes he's started calling him Kaneki before he even realized it.
Kaneki the cat would sometimes fall asleep on his belly and Hide would feel a lump building in his throat and and an empty feeling in his chest.
One day Haise forgets his umbrella in his haste to a bookshop, and he starts muttering curses under his breath, shielding his books under his arm as he hurries to the nearest bus stop. A stranger would then share his umbrella with him with a dazzling smile and he would feel so relieved he actually gives him back one of his own. The stranger would then tell him to keep it as he got off the bus and hurriedly climbed the stairs to a building, and Haise would be left dumbstruck and mid-protest staring at the retreating back of the blond man, feeling warm at his kindness.
Haise is a ghoul and he knows Akira knows it too. He doesn't want her pity when he asks her for a hug, but for her to mean it when she complies. He knows he never had the right to ask for a friend.
It's just he sometimes wishes he had one who would gladly just hold him for hours on end.
Sometimes, not even Kaneki the cat can relieve some of Hide's loneliness. Those times he just ends up watching their old graduation photos or the ones of their coming of age and he tells himself he isn’t pathetic and lonely when he realizes how handsome Kaneki was even in those ugly, awful ones Hide had taken just to embarrass him.
Every other time Hide is allowed to come back to Japan, he wishes for another chance encounter. Maybe he puts two umbrellas in his backpack on purpose.
Hide's wish is still the same despite it all. He just want for Kaneki to find his happiness, even without him.
When the rumor had it that he's gone in full Kakuja form during the last operation and he's now being restrained with heavy Rc suppressant in the hospital as they wait for the order of confinement in Cochlea, Hide doesn't even bother calling his dad. He books the first flight to Japan and spends the whole night wishing that just this once he could make it on time.
Hide doesn't know what the fuck he's doing when he just ignores the medical staff who are pretty much staring at him. He just keeps squeezing his best friend in his arms until he wakes up and finally looks at him, not at 'some stranger', and squeezes back.
I missed you, Kaneki would brokenly whimper in his arms as an apology. Dude, Hide would reply, hesitantly letting go to see his face, his own voice wobbly as the implications sink in. I even named a cat after you, he would counter, laughter still trembling on his equally tearstained face.
