because I am a sadist to my characters, especially my sweet sensitive small science son

NOTE: this is a "canon compliant AU" in which the plot of BH6 evolves 90% the same but there's extra stuff. it's basically a rewrite of certain scenes with 100% more sad Hiro. if you've read Five Alarm Death March and Sophie's Universal Singularity (which you should've if you're reading this story), then you'll recognize some of the situations.

mentions of self harm, gore, suicidal thoughts and eating disorders within, read at your discretion

disclaimer: I don't own the copyrighted material within

Tadashi smiles at Hiro and it's his big beaming "I'm so proud of you little brother" times twenty because now Hiro's in college, about to change the world with that big brain of his. They're all going to celebrate, Fred already prodding Aunt Cass about what's on the menu for tonight, and Hiro ducks his head when Tadashi speaks into his ear, "You're incredible."

Hiro can be a quiet thing at times, so the grin stretching across his face just lights up Tadashi's world. Hiro straightens up, ears red, and yells, "Wait, gotta get my neurotransmitter from my display!" and heads back into the building. Tadashi follows, watching his little brother weave between people like the toddler Tadashi raised. He hopes that his parents can forgive him for wanting Hiro to be his, because Hiro is his otouto, his baby, and

and there's an explosion, there's fire racing up the walls and it's like a car crash but so much worse.

People are screaming and knocking each other over and where is Hiro? Hiro is cowering by a burning exhibit, holding onto a bleeding arm and his wide brown eyes are so filled with fear that any hesitation Tadashi holds burns away. Hiro needs to live, someone has to help and Tadashi is the embodiment of fraternal loyalty.

He carries Hiro away from the flames but they're trapped, too many flames and dead parents and Hiro's gasping "Niisan" into Tadashi's shirt and he only does that when the fear and pain is too much. He hears people yelling for Prof. Callaghan and oh god no, not his mentor too, he needs to get Hiro out and then he's going to save everyone else because no one deserves to die in flames.

They finally escape and Tadashi sets Hiro down past the stairs, watching his brother cough away the toxic smoke clinging to his lungs and skin. Tadashi hears a cry of pain from within the inferno and he has to help, he can't let someone die like this. Hiro says no and Tadashi kisses his forehead, "I love you," before returning to the flames.

Inside he sees Prof. Callaghan with the neurotransmitter, sees his mentor make eye contact before resolutely surrounding himself with Hiro's microbots, his brother's stolen microbots, and runs back towards the doors.

He's ten feet away before the fire explodes again and his skin burns so hotly that it's freezing and Hiro's crying, Hiro's choking on the scent of his niisan burning and holding out his arms that only catch burning glass into the delicate skin. Tadashi wants to crawl away from the pain into those arms but then a ceiling beam falls and

he tells his parents he's so, so sorry.

Hiro doesn't eat after he passes his brother's bones between chopsticks. He doesn't eat after his brother's urn is interred with his parents' in the graveyard, or at the funeral reception, or the nights after because Tadashi is dead and Hiro smelled him burn and how is he supposed to eat after that?

He can feel his arms ache hollow under his bandages and his stomach tremble empty but he can't do it, he can't get out of bed and greet the sun so much less than consume food. Aunt Cass comes to collect last night's uneaten plate and Hiro curls up under his covers, forehead burning from the memory of Tadashi's last words and his own self-hatred because Hiro never said I love you back.

He cries and he cries so hard that his heart bleeds, his mind gushes grief between his fingers as he reaches out towards the flames and screams for his brother. He only collects burning flakes of skin and glass embedding into his skin, and Hiro pulls at the stitches in his arms. It hurts and the tang of blood clogs his mouth with memories of skinned knees and Tadashi kissing them better when his parents couldn't, and

and it hurts so bad, Hiro wants to drop dead and join the rest of his family.

He kicks off his blankets and considers the edge of a discarded screwdriver.

But then Mochi slinks into the room and curls up on his lap, purring away a storm and nuzzling against his aching arms, and Hiro hides his tears of shame and guilt into Mochi's fur. What about Aunt Cass, the one pillar of strength in his life when the burning roof has collapsed around him? What about Tadashi's friends, who still call him time to time to remind him that there's a sun outside and all he has to do is step outside? What about Mochi?

Hiro doesn't step outside, and he doesn't eat, but he's alive, and that's a victory within itself.

Baymax is concerned for his patient.

Hiro is a young adolescent a bit behind on the growing curve but now entering puberty, yet his body weight is low, his injuries are not healing as quickly as they should, and there's a panicky sadness to his movements that has no place in a healthy patient. When Baymax downloads a database on grief and personal loss, he understands, and he goes along with Hiro's plan to apprehend the masked man.

Using San Fransokyo's wifi, he also downloads more information on teenage grief, teenage coping methods, and things he deeply prefers Hiro need not suffer through. Tadashi is here, yet he cannot help convince Hiro to eat and stop tearing at his stitches, so Baymax will have to do it himself. It's easy enough to remove the torn stitches and sew the wounds back up, but Baymax worries about scar tissue and the far away glaze in Hiro's eyes.

Alas, they are unsuccessful in apprehending the masked man, and Hiro sustains more injuries to his arms and the beginning phase of hypothermia. Baymax watches Hiro draw in on himself, looking "down" or "blue" as outward behavioral symptoms of depression are called, and applies more comforting contact to try and bring Hiro out of a self-destructive shell.

The treatment is partially successful, and the night after Hiro gathers his scans to create suits for his companions, Baymax watches him avoid sleep and avoid eating. "Hiro," Baymax advises, "during adolescence, 10-12 hours of sleep is recommended for optimum health and mental performance."

Hiro snorts and mumbles about how sleep is for the weak in Japanese; thankfully, Baymax can understand 20 languages, and counters with "It is also recommended for moderately active 14-18 year old males to ingest 2,400 to 2,800 calories per day. You have eaten approximately 1,000 calories in this 24 hour period," in Japanese.

Hiro flinches and puts up defensive barriers. "I'm fine, Baymax," he says, "just leave me alone."

"You are my patient," Baymax needs Hiro to understand this, "I cannot leave you alone while you require my attention."

"Busybody," Hiro hisses and moves to tear at his stitches again. Baymax catches his hand, applying a slight vibration to his finger servos, and Hiro looks down in shame. He gulps past tears, despite it being alright to cry when emotionally distressed, and whispers, "I'll be alright, just...just let me finish this first, ok? Then I'll go to sleep."

"You have lost 10 pounds in the 3 weeks since I first scanned you," Baymax picks up Hiro's discarded dinner, "I highly recommend consuming this and going to bed." Baymax blinks, "You are my patient, I only want you happy and healthy."

Hiro's squeezes his eyes shut, and he eats the rice and steamed vegetables (he avoids the cooked chicken, Baymax stores this information for later) before crawling into bed and curling into himself. His breathing hitches and Baymax wants to ask why Hiro is doing this to himself, but he already knows the answer, and Hiro eventually falls asleep. Baymax regrets causing Hiro emotional distress, but someone has to push him out of spiraling self-destruction, and Tadashi isn't quite here for that.

Hiro is exhausted when they touch down on Akuma Island, shaking and light headed and maybe he should've eaten more of his breakfast today. Too late for that though, and he slouches within the group, he wants to reach out and take comfort in their colorful warmth but the burn in his stomach and arm hold him back.

Instead he watches as a pilot is consumed by flames. His heart stutters to a stop because that was someone's daughter, maybe someone's older sister, and now she's burned to death in the black hole and her ashes will smell so sweet against the ozone of her suit. And she looks so determined before she dies, Hiro recalls that expression from a lifetime ago.

When Tadashi took him to the nerd lab, Prof. Callaghan (and oh, Prof. Callaghan, he burned away too) showed them a picture of his former bot fighting daughter, Tadashi's former TA and friendly associate. Tadashi and Prof. Callaghan were into scare tactics, and the story behind the picture of her at the oral surgeon still makes Hiro cringe.

She had wild hair, eyes filled with challenge, and all of her front teeth were missing, soon to be replaced with implants to save her pretty face; Yama wasn't just big talk, after all, and he didn't like losing. That was one of the reasons why Hiro gave up bot fighting, he didn't want his face smashed in like her. Maybe if he avoids bot fighting and anything to do with Krei, he also won't burn to death like the pilot or Tadashi or his parents.

But maybe he'll be like Callaghan, because Callaghan is the man behind the mask and he admits to letting Tadashi die. Sure, he didn't actively hold Tadashi down as the building exploded, but he caused the fire, he stole the microbots for himself, and he allowed Tadashi to run back to the stairs and die ten feet away from Hiro's outstretched arms.

"He went in there to save you," Hiro feels his face and voice twist up like limbs shriveling up into charcoal, crackled bones ready to be passed by chopsticks.

"That was his mistake!"

And Hiro feels a tear run down his cheek to stain his lips with salt, making the sweet taste of Tadashi's body so much more bitter in his churning stomach. He recoils, one step two step back to Baymax who scans Hiro and can see the hysteria building. He hyperventilates past the horror and grief lodged in his throat and Honey asks if he's ok but Hirois not ok. Hiro's starving and he wants to rip out his stitches and gouge his arms open and he wants Callaghan dead, Callaghan killed Tadashi his older brother his niisan his father figure

why does he deserve to live?

Hiro clutches Baymax's caregiving chip to his lips, kisses the forehead of the little smiling doctor, and his voice is possessed with hate. "Destroy him, Baymax," Hiro sees Callaghan run away in fear and yells after him, "Rip him apart!"

But Hiro's once-friends stop him and Callaghan gets away and Hiro flies back home, fingers shaking with rage and hunger and he won't stop until Callaghan is nothing but ashes in the wind.

Tadashi is here.

He's in the ground but he's also he's in Baymax's archives and Hiro watches his brother. Tadashi is nervous in these videos, frustrated, tired of dealing with his faulty robotics project and his bonehead wayward brother. Tadashi is so happy at the end, so overjoyed to have built Baymax and so excited to make Hiro meet him and lead them both into a future that could've been everything that Hiro wishes for.

They could've stopped Callaghan together, they could've gone to school together, they could've lived together and gotten older together and changed the world together and Tadashi is gone

but his love is still here.

Hiro cups his hands over his mouth to swallow down the raw sobs that tear his insides apart, then wipes at his eyes and laugh-sobs in joy-agony at Tadashi through the vinyl. He remembers that Tadashi's last words were "I love you", and Hiro breaks down completely, resting his forehead against Baymax's middle and balling his hollow hands into fists that want to beat himself senseless for violating Baymax, for betraying his friends, for ever being like Callaghan and not like Tadashi.

Baymax hugs him close, and says, "It's alright to cry."

Hiro does, for a long while.

And when he's done he wipes his eyes again and gets down into a proper bow and shivers, "I'm so, so sorry."

Baymax forgives him, and his friends—they had watched everything, they'd seen Hiro's rage and Hiro's absolute sorrow—do the same. Gogo hugs him and then the rest, he feels warm in their arms and it's not Tadashi at all but it soothes some of the pain away, he feels small again in the arms of Aunt Cass and oh, she'd be so disappointed in him.

"We're going to do this right," Gogo says, and Hiro wants to believe her.

So when he sees Abigail, wild haired eyes holding a challenge former bot fighter Abigail Callaghan who used to TA Tadashi's aerodynamics class, disappear into the portal, Hiro knows what to do. He's going to stop Callaghan, stop his own rage from poisoning what Tadashi would've wanted for his life, and they're all going to do it right together.

The portal's inner dimension is so beautiful, and so terribly cold that it burns at Hiro's unprotected legs and his shaking fingers; his stitches ache and for one he wants to leave them be. He wipes away the frost from Abigail's windscreen, and swears that there's frozen teardrops on her eyelashes, or maybe those are his because Baymax's thrusters are broken and he can't lose Baymax too.

He stalls for time they don't have and beg for answers that don't exist, and he has to let Baymax go. Technicolor smoke curls around his ankles and he's kneeling in front of another grave, arms outstretched to gather more broken glass in his wrists. Baymax is not Tadashi but he has Tadashi's love and his own soul and he's already Hiro's best friend, how can he be satisfied with his care.

He hugs Baymax close and cries some more, and feels his tears freeze to his cheeks. This will never be fair and he will battle against this hurt for the rest of his life along with all the rest, and Hiro's going to have to live with that.

Hiro sits back and chokes out, "I'm satisfied with my care," and watches Baymax fall alone into the deep, crematory smoke curling around the last piece of Tadashi that Hiro had.

He and Abigail land harshly, and Hiro rests against the pod, getting his sobs under control before he has to face reality because life doesn't care much for the Hamada family. He doesn't answer Wasabi's question and turns to look at Abigail, who stutters back into consciousness. Her eyes meet his, wide and confused and filled with tears that neither of them can explain, and Hiro decides that he wants to get to know her, Tadashi's TA and friend and the girl that Callaghan destroyed Hiro's life over.

She raises a weak hand and Hiro's hands remind him that he's running on multidimensional fumes, and Wasabi has to carry him out of the rubble before the cops show up.

He eats half a sandwich when prompted, because he can still remember Baymax telling him to.

Hiro is accepted into SFIT, and there's a therapist there who doesn't ask why Hiro is there, only how he hurts. Aunt Cass and his friends aren't supposed to know but Hiro bets that they do, and he hopes that they don't think him weak for seeking out help after he whited out from hunger in the bathroom and tore open those damn stitches again. He's sick of the aching injuries, the scar tissue he knows will be ugly, and maybe Baymax isn't here to help but Hiro Hamada is still alive and he might as well take care of himself.

It helps, talking to someone without the context of being a Big Hero and a little orphan three times over, and he is comfortable eating vegetables and grains by the time he rediscovers Baymax's chip.

Then everything is focused around rebuilding Baymax and his own classes and reaching out to Abigail, who is his TA in two classes. She goes to the therapist too, for rage issues directed at her father and herself, and sometimes they hang out in the reception room, checking over improved Baymax 2.5 schematics. She's confident and blunt and a little fragile, and Hiro's heart can't handle losing anyone else but he takes the chance and starts to love her anyway.

She craves physical contact and her hugs are almost as good as Tadashi's fantastic without the comparison, and she gently introduces him to chicken udon. Hiro chokes on the first bite but the second tastes good, and he finishes the whole bowl while Abigail pays for everything.

His friends are around him, keeping him warm and on track with his health, and when Baymax is finally operational, he's halfway back to a healthy weight. With Baymax's healthcare companionship, and Abigail stuffing him with somewhat healthy-ish food at Shizu's and Nene's, and Gogo and Honey's parents feeding Hiro when he goes over to their homes to study, and Wasabi teaching Hiro how to cook vegetarian meals, and Fred flat out buying whatever Hiro craves, he's back to that weight and a bit more very quickly.

Sometimes he slips up into bad habits, but these moments are rare in the rush of flying around skyscrapers and spending sleepovers at the lab with his friends and saving older brothers from burning buildings for the sake of little brothers. Hiro will always have that grief and rage and self-destruction hiding beneath his arm's scar tissue, but Baymax applies treatments to lessen the build up, and Hiro's loved ones never shame him for it.

Hiro works with Aunt Cass on Thursdays, savoring her presence, and in the other days he's at school and around San Fransokyo, savoring his friends and not-quite-said-out-loud neesan. They're alive and they're there for him and it's a family he never knew he'd get after losing his birth one but it's his all the same.

And it's not perfect without Tadashi, Hiro still wishes that he could be here and be alive for Hiro to rely on and tell secrets to and try and make proud. But Tadashi is with their parents and maybe they're watching Hiro save the day and save himself, and that's good enough for his happy ending.

I am so sorry Hiro, I promise that I adore you as more than just a punching bag.

Anyway, this is how I would've written BH6 (minus the more obvious eating disorder and self harm moments because this is a bit intense for small children), so be happy that I don't work for Disney XD