Chapter 4: Practice


It had taken the better part of the rest of the day for Tadashi to gather himself up and walk home. He was so jumpy by then that when a friendly-looking cyclops oni walked up to him and asked him if he was okay, he immediately bolted, ducking through the crowds, heedless of the chaos he was causing. He didn't stop until he was sure he'd lost anyone who might be following him, and only then realized that he'd overshot the street that led him home and that he needed to double back about three blocks or so. A passing faun with flowers for hair leading a group of children that glowed like coals tried to offer him directions, but Tadashi's hitodama suddenly flared up with his fear, causing a nearby pile of garbage to burst into flames. Rather than deal with the mess, Tadashi ran again, leaving the faun cursing after him while the glowing coal children happily jumped into the flames and danced around.

By the time he arrived at home, it was almost nighttime, and he could see Aunt Cass switching the sign on the cafe door from open to closed. He felt a pang in his heart at the sight of her. He hadn't seen her since his accident at the wake, and he could immediately spot the changes his death had wrought on her. There were dark circles under her eyes that even her heaviest make-up couldn't hide, and her clothes and hair were not up to her usual standards of neatness. She also looked like she'd lost a bit of weight already. Still, there was a smile on her face, even if it wasn't as big and bright as he was used to, and Tadashi had to remember that this wasn't the first time his beloved Aunt had dealt with a loss of family. His heart went out to her, but he knew she was strong.

Besides, between Aunt Cass and Hiro, Tadashi knew who really needed his attention at this point, and so he headed towards the garage instead of into the cafe. He could see the light beneath the large metal door, and knew Hiro must be working on something inside, though on what he had no idea. Maybe Hiro was trying to make more microbots to compensate for the ones that had been stolen. Tadashi phased through the wall again, prepared to find Hiro bent over a desk with his face screwed up in concentration as he worked on the tiny components of his invention.

Only Hiro wasn't at his desk, and he wasn't working on microbots. Tadashi was momentarily stunned when he realized the bulky armoured person standing in the middle of their garage lab wasn't in fact a sumo wrestler, but Baymax. In carbon-fibre armour. What.

"Yeah! Fist bump!" Hiro announced, practically bouncing around Baymax like an excited puppy.

Baymax simply blinked in confusion. "'Fistbump' is not in my fighting database."

Hiro shook his head and tried to explain what a fist bump was to the nurse robot, but Tadashi was too busy taking in Hiro's work to really pay attention. The armour was relatively well made, despite the fact that Tadashi knew that carbon fibre wasn't Hiro's favourite material to work with. The joints were reinforced, and everything seemed to fit well together, though as he hadn't really given Baymax knees, the leg armour looked like it lacked mobility. At first, Tadashi thought that maybe Hiro had put armour on Baymax to protect his invention, but then he spotted the scraps of broken plywood spread out everywhere.

All over the garage, any and all pieces of furniture or junk they'd collected over the years were lying on the ground, smashed to pieces. A couple of cinder blocks had been set up side by side just like they would be for a martial arts demonstration, with a splintered board lying between them. A glance at Hiro's computer screen showed several martial arts videos cued, and a motion capture of Baymax frozen in the same position as the man in the video, in the middle of a high kick.

Oh god. His brother had turned Baymax into a giant battle bot.

Tadashi was gonna kill him.

But before he could give in to the urge to strangle his little brother, Hiro was already bouncing over to Baymax and jabbing his elbow into the robot's side. "Alright, let's go get this guy," he told Baymax.

Only Baymax wasn't listening. He was looking over across the room, blinking slightly. Tadashi followed his gaze, noticing the computer terminal he was standing next to was making strange noises, and the screen was glitching. Confused and more than a little annoyed that of course it was hiscomputer that Hiro had apparently managed to break, he leaned closer to inspect the screen, wondering what was making it fritz out like that.

Just as he reached out to touch the keyboard, the entire computer suddenly let out a high pitched whine and then sputtered and died. Meanwhile, the computer screen went dark in a shower of sparks.

Tadashi jerked back, just as Hiro ran over. "Aww, man!" Hiro whined. "What the heck? No!" He dropped down under the desk with a string of curses that he sure hadn't learned from Tadashi, and started fidgeting with the wires, trying to figure out what had gone wrong. Judging by the increasing volume of swearing, it wasn't going well.

Tadashi had moved away from the computer, startled by the sparks, but that had brought him closer to the vending machine full of snacks they'd installed in the garage shortly after turning it into a lab space. When he came too close, it also started to make worrying sounds and spark a bit, though not nearly as badly as the computer had. With a jolt, Tadashi suddenly remembered the old myths about ghosts and how they could mess with electronics. It looked like those myths were true. Very carefully he made his way to the center of the room, doing his best to avoid getting too close to any of the machinery they had lying around the lab space.

It wasn't until he'd started checking around himself for any more equipment that he might mess with that he noticed Baymax watching him. Or at least, that's what it looked like. Except he was a ghost, completely invisible to the living world, there was no way the robot could see him.

But when he took a deliberate step to the side, Baymax's head turned to follow. When he stepped back, Baymax's head returned to center. And when he jumped up and down, Baymax bobbed along. It was impossible, there was no way Baymax should have been able to see him, but somehow he was following Tadashi's every move.

"Unbelievable," Tadashi whispered to himself.

Just then, Hiro crawled out from beneath the desk, grumbling under his breath. He had a handful of wires and a smudge of soot on his cheek. "Stupid fan blew, I'm gonna have to replace that later," he grumbled. With an irritated motion he tossed the wires over his shoulder into a bin of spare parts before striding back over to Baymax. "But that can wait. For now, we've got a bad guy to catch. I'm not going to let him get away with what he did."

At once, Tadashi knew who Hiro was talking about. The Onryo.

His entire body went numb with fear as the feeling of shadows crawling all over his body and choking him shot through him. The experience had been bad enough, feeling like dying all over again, but he was already dead and couldn't be killed again. Who knew what would happen if those shadows got a hold of Hiro. He couldn't let Hiro go near the Onryo, he just couldn't.

"No!" he shouted, even though Hiro couldn't hear him, instinctively reaching out to grab at Hiro's shoulders. "Please, Hiro, no! You don't know what he is! You don't know what he'll do to you!" Once again, his hands passed right through, catching on nothing, but Tadashi couldn't give up. He kept trying, grasping at Hiro's shoulders, hair, hoodie, anything and everything he could reach, anything that could stop Hiro from going.

Oddly enough, Hiro twitched, rolling his shoulders like he could almost feel Tadashi's touch, but he still didn't stop.

"Come on, Baymax," Hiro opened the garage door and gestured the robot forward. Baymax glanced back at Tadashi one more time, before starting to follow after the younger Hamada.

"No, please, no!" Tadashi screamed, frantic now. In desperation, he dashed around in front of them, holding out his arms like he could somehow physically block Hiro from leaving. His brother walked on obliviously, headed straight for him, and Tadashi reached out to push him back with all his strength.

The world flipped again. Up was down and down was up and he wasn't sure where he was or who he was and there was blurs of colours and lights whirling around his head like a galaxy until suddenly the world righted itself and he was Tadashi Hamada again. Only he was facing the opposite direction he had been before. And the world had somehow gotten a lot taller.

A quick glance back up at Baymax confirmed his suspicions. He had somehow taken over Hiro's body again.

He stood there for a moment, trapped in indecision. On the one hand, Hiro couldn't run off to confront the Onryo when Tadashi was controlling his body, so he would be safe, but on the other hand Tadashi was controlling his body!

"Oh man! Oh man, oh man, oh man. Not again! How did I? How do I? Oh god, what did I do?" Tadashi's hands instinctively flew to his head. He'd previously had a habit playing with his ever-present hat whenever he was very excited or upset, exactly like he was right now. If he wasn't wearing his hat, he'd grab at his hair instead. Except this time instead of familiar fabric or short spiky hair he was expecting, his fingers sank into Hiro's much thicker and longer locks. Already on the border of a total meltdown after the stress of seeing Baymax in armour, Hiro attempting to find the Onryo, and accidentally possessing his brother again, this was the tipping point.

There was a flash of heat and light, and suddenly the couch that they'd left in the lab for those long nights of work burst into flames.

There was a moment where Tadashi could do nothing but stare at the bright flickering flames slowly consuming the ratty old furniture. His mind had gone blank with fear. It reminded him much too strongly of the fire at the showcase hall, the fire that had taken his life and turned him intothis, and the raw terror had consumed him. His vision was filled with nothing but fire, his lungs choking on thick black smoke and the smell of burning wood and fabric. Someone was screaming somewhere, sounding so painfully familiar, but the sound was muffled, like someone had shoved cotton into his ears.

He didn't know how long he had been standing there, staring. But suddenly there were thick armoured arms around him, pulling him away from the couch. A massive round form stepped in front of him, blocking his view of the fire, and suddenly Tadashi realized it was Hiro's voice he heard screaming like that. Except it was him. He was screaming in fear with Hiro's stolen voice in Hiro's stolen body. He cut himself off, but his breathing was still erratic and out of control. He could see his vision getting fuzzy around the edges, like he was about to pass out, and he couldn't help but hysterically wonder what would happen if he fainted while in Hiro's body. Would Hiro wake up with Tadashi still trapped inside? Would it be enough to jolt him out? What if it somehow hurt Hiro?

These thoughts were not helping him get his breathing under control, he thought angrily, but he couldn't seem to stop himself.

Just then, the figure in front of him reached out and pulled him into a tight but soft hug. Tadashi stiffened for a moment, but then finally recognized who was with him. It was Baymax, who had removed most of his body armour, and was now slowly moving Tadashi away from the couch to the far corner of the lab. He was also talking to Tadashi in his normal soothing tone, though it was only just now starting to get through Tadashi's panic.

"...as well as difficulty breathing. Diagnosis: panic attack. Treatments include cognitive behavioural therapies, medication, and breathing exercises. I shall guide you through one of these now," Baymax instructed, the screen on his chest lighting up and displaying a helpful diagram on what to do. "Please follow along with the instructions you see on the screen."

Tadashi did just that, taking deep breaths and holding them as Baymax displayed a helpful timer along with the diagrams. After a few minutes, he felt himself calm down, though he couldn't help but still be a little concerned about the couch. Most of their stuff in the garage had been fireproofed after one too many experiments gone wrong in their youth, but it was still a sizeable blaze.

"Okay. Okay," Tadashi took one more deep breath, and felt his shoulders drop. "Thanks, Baymax, I think I'm okay now."

"I am happy to hear you feel better. Please let me know if you feel any of your symptoms returning."

"I will, bud. Thanks," Tadashi reached up as far as Hiro's scrawny arms could reach and patted Baymax thankfully on the arm.

"You have been a good boy, Tadashi," Baymax told him. "Have a lollipop."

Tadashi chuckled and took the offered sweet, although he only tucked it into Hiro's hoodie pocket rather than open it. Lollipops were more Hiro's thing, something Tadashi had coded into Baymax's design more as a joke than anything. He figured his brother would get a kick out of it, if nothing else. Besides, this wasn't the time for candy. Now that he was calmer, he needed to find the fire extinguisher and put out the couch before it set of the fire alarm upstairs in the cafe. Aunt Cass would throw a fit if that happened. Tadashi started rummaging around the edges of the lab space, looking for the elusive red canister. Now where the heck did they put it after last time?

And then what Baymax had just said registered in Tadashi's mind, and all thoughts of fire extinguishers was forgotten.

"Wait, what did you just call me?" Tadashi whirled around to face his invention. The nursing robot tilted his head and blinked.

"Tadashi," Baymax repeated. "Is this not what you would like to be called? Would you prefer the more formal Mr. Hamada, or Hamada-san?"

Utterly shocked, Tadashi could only shake his head. "No, no, Tadashi is fine. It's just...how did you know it was me?"

Baymax's finger rose in his typical diagnostic explanation pose. "I have detected a recurring electrical anomaly in my circuits for which there was no identifiable cause. I have found on two occasions now that this usually occurs shortly before the behaviour, speech, and mannerisms of my patient Hiro Hamada change and become identical to those found in my creator, Tadashi Hamada. My research into loss and grieving has identified the concept of 'life after death' to me, and further research suggests that one possible theorized outcome is to become a spirit or ghost, which are suspected to cause electrical anomalies with their presence. I have thus concluded that you are the ghost of my creator, Tadashi Hamada. Is this not correct?" Baymax asked with another tilt of his head.

Tadashi's jaw had dropped open and he stared at his robot. After a moment, he realized Baymax was expecting a response, and he quickly shook his head to clear it. "No, that's...that's exactly it. You're right, I'm...I'm Tadashi. I just can't believe you figured that out on your own."

"Caring for Hiro has already caused me to learn and go beyond your original programming, as he is a most complex patient. I do not know if I will be the best health care companion for him, though he has already helped me improve by teaching me karate."

"I know, believe me, I know." Tadashi told him ruefully, thoroughly impressed with his creation at the moment. He'd poured his heart and soul into Baymax's coding, and he'd made sure that the AI could learn to better keep up with the ever-evolving medical field, but he hadn't realized that Baymax's programming would be able to make such leaps of deduction. He was kind of proud of his robot. Especially if he was trying to keep up with Hiro.

"Hiro can be a handful. But you're doing your best buddy, and that's all I can ask of you. I'm trying to keep an eye on him too, though if it's affecting your circuits, maybe I should stay away."

"I am not affected to any degree that will compromise my programming."

"That's good to hear," Tadashi said in relief. Just then the burning couch let out a particularly loud crackle, reminding Tadashi that it was still burning away. "Oh crap!" Tadashi yelped, "Baymax, can you find the fire extinguisher anywhere?"

"I believe it was used as a target when testing out my new karate programming," the robot confessed.

Tadashi cursed, looking around for another solution. It was a testament to how well they'd fireproofed the lab that nothing else had caught yet, though he was a bit concerned no smoke detectors had gone off. He looked around frantically for something to put out the blaze, but other than Hiro's half-finished soda on the computer desk nothing immediately presented itself.

"Come on, Hamada, think!," Tadashi hissed to himself, face scrunched up in concentration. Just then, one of his hitodama floated past in front of his face, and he got an idea. "That's right. If my powers can start a fire, maybe they can put it out! That makes sense, right?" He looked back at Baymax, who merely blinked at him. No help there, of course.

"But how?" he whined out loud to himself, racking his brains for an idea. He tried thinking back to Mrs Matsuda's teachings. She'd said his powers were connected to his emotions, right? And being upset had started the fire. So if he was calm, then...maybe that would help. He tried taking a few deep breaths, focusing on the feeling of being alive, even if it was borrowed life. He focused on Hiro.

A feeling of cool power rushed through him, making him feel strong. He could do this, somehow he just knew it. He could feel the blood rushing in Hiro's veins, feel the air in his lungs. His little brother was with him, strengthening him even if he didn't know it. With Hiro's help, Tadashi felt he could do a calming breath, he reached out and gestured towards the couch, focusing on the heat and fire with all of his senses. He thought of the feeling of it, the warmth and light, and tried to hold it in his mind. Then, he slowly lowered his hands, imagining the flames lowering along with it.

Tadashi couldn't see it, but for a moment Hiro's normally brown eyes flashed brilliant gold and blue, matching the flames of Tadashi's hitodama.

It was almost effortless to smother the flames, and Tadashi surprised himself with a burst of laughter. He felt powerful, in control, like he actually knew what he was doing for the first time since he ran into that burning building. It was a wonderful change of pace, and he revelled in the feeling.

When the couch was put out, it was completely ruined, the fabric turned to ashes and the frame no more than a charred husk, but aside from the still slightly smoking remains of the couch there was no sign that there had ever been a fire at all. Tadashi looked down at his - Hiro's - hands in wonder. He'd done that.

"Wow," he whispered to himself. After a moment he looked up at Baymax, who had been silently watching all the while. The robot blinked at him, and although he had no mouth, Tadashi could have sworn he was smiling.

It faintly occurred to Tadashi in that moment that if possessing Hiro gave him such a boost in control and power, perhaps the Onryo was possessing someone too. Maybe that's where his overwhelming strength had come from. If Tadashi's theory was true, then maybe, if he was possessing Hiro, just maybe he could actually match the Onryo's power, instead of being completely overpowered like last time.

He discarded the thought almost as soon as it formed. Even if he could win, he would never put Hiro at risk like that. The fact that he'd even considered it, as brief as it had been, left him feeling slightly sick. No, he still wanted to keep Hiro as far away from that monster as possible.

To further remove the temptation, Tadashi decided he needed to get out of Hiro's body ASAP. But how was he going to do that? Last time it had taken a fall out of a third storey window and bouncing off of Baymax's belly, and he wasn't interested in repeating that experience. But he couldn't seem to will himself out, as much as he furrowed his brow in concentration, and jumping around only seemed to be tiring him out.

He even asked Baymax for suggestions, but the robot of course had nothing.

Just as Tadashi was about to tear Hiro's hair out in frustration, he heard a very familiar purring sound coming from outside the garage.

"Oh hoh hoh!" Mochi chuckled as he sauntered into the lab space, taking in Tadashi-in-Hiro, the half-armoured Baymax, and the blackened and smoking remains of the couch in one sweeping glance. He tisked and shook his head, before strolling up to the computer desk. He quickly hopped up onto the rolling chair and then to the desk itself, settling himself gracefully and curling his twin tails around his paws. "What have we here?" the nekomata asked, the markings over his eye mimicking raised eyebrow.

Tadashi glanced around, seeing the mess around them, and ducked his head sheepishly, rubbing at the back of his neck. "Heh, oops?" Tadashi said.

"Hello, Hairy Baby," Baymax greeted with his usual circular wave, before waddling forward with his arms outstretched. A moment later Mochi was sitting in Baymax's arms, purring like mad while the robot stroked the top of his head.

"I must say, Tadashi, this is clearly your best invention yet. A soft cat bed that also administers pets, absolute genius!" Mochi praised, eyes closed in happy bliss. Tadashi opened his mouth to correct the cat, but then thought better of it. At the moment, that was a pretty accurate description of Baymax.

He didn't bother asking how Mochi knew it was him. The cat could possibly see him inside Hiro somehow, and if he couldn't he could probably see the hitodama.

That's when Tadashi remembered, Mochi was a nekomata. They were supposed to be associated with the dead and all that, and Mochi seemed to know a lot about ghosts and supernatural things. Maybe he knew how to unpossess someone!

Mochi's one eye opened slightly when Tadashi asked him about it. "Hmmm? Are you stuck or something?"

Tadashi's shoulders slumped in embarrassment. "Yeah."

The cat grinned at him.


Mochi was a wonderful pet, always ready to curl up in your lap or at your side whenever you needed a bit of company, but he was an absolutelyhorrible teacher. It didn't help that he kept referring to different parts of Tadashi-in-Hiro's body as 'paws' or 'the muzzle', and he kept getting distracted whenever Baymax started petting a particularly nice spot. It left Tadashi more than a little annoyed. He made a mental note to pull a poltergeist and 'accidentally' knock the family's stash of catnip out of the highest shelf the next time Mochi was nearby. Let's see how the nekomata liked it when he couldn't figure out how his body worked.

But thankfully, after nearly forty minutes of struggling, Tadashi finally figured out what Mochi was trying to say.

"So I just focus on finding Hiro, like his soul or something, within the body and I...push off of it? And then I should just...separate?"

"Like oil and water," the nekomata confirmed.

"Okay, it's worth a shot." Tadashi looked down at his hands, Hiro's hands. Though they were smaller and thinner they were almost as familiar to him as his own, the multiple calluses and scars practically mirrored on his own hands. Hiro's arms, scrawny and smooth, his skin far too pale after weeks of cooping himself up indoors. Hiro's baggy clothing that practically swamped his frame, comfortable but ill-fitting. His hands sunk once more into Hiro's thick hair, tugging at the strands. He'd never let his hair grow this long, and the foreign feeling of it tickling the back of his neck was enough to help him focus on the fact that this was Hiro, it was Hiro's body, not his own. This was his baby brother.

And just like that he could see the disconnect.

After that, it was as simple as breathing to just reach out and pull himself out. It kind of felt like taking off a particularly tight set of wet pants, like fabric clinging and catching and not wanting to let go, except it was all over his body and the fabric was Hiro. But with a 'pop' Tadashi came loose, Hiro's body falling to the ground. Baymax had to quickly drop Mochi in order to catch Hiro before he could hit the ground, to the cat's unpleasant surprise. Tadashi didn't feel too sorry for him at the moment. Mochi darted out of the garage, looking back at them all with a miffed expression and a toss of his tails.

Baymax quickly scanned Hiro to check him for any injuries, and announced that other than a slight electrolyte imbalance Hiro was completely fine, but Tadashi almost didn't hear him. He suddenly felt impossibly tired, like all of his energy had been sucked out to remain with Hiro. Even his hitodama looked exhausted, drooping low enough that they practically skimmed the ground every other orbit.

He stuck around just long enough to watch Baymax help a groggy but awake Hiro to his feet before he decided he needed to lay down for a while. Even though the couch was nothing but ashes at this point, the thought of dragging himself up three flights of stairs, even if he could just walk through the walls, almost made him want to cry. So he flopped down on the ruins of the couch, shifting in the pile of ashes and soot just enough to get comfortable, and then let his eyes slide shut. He had just enough time to marvel at the idea that ghosts actually could sleep before he faded.

Baymax didn't see him go, because he was too busy taking care of Hiro. The robot carefully set Hiro on his feet and then took a step back, though staying close enough that he would be able to catch Hiro if he passed out again.

"Ugh, what happened?" Hiro asked confusedly, rubbing at his head. "Baymax?"

Baymax looked down at him. "You have experienced a phenomena known as possess - "

The robot didn't get to complete his diagnosis, because at that moment Hiro spotted the remains of the couch. "Aww man!" he shouted, pushing past the robot and running over. He looked at the pile of ashes with a mixture of annoyance, confusion, and dismay. "What the heck happened? Was this from the computer? And, dude! Where did your armour go? Oh god, what time is it?"

Rather than wait for an explanation, Hiro immediately started dashing around the garage, gathering up the discarded pieces of Baymax's armour and slotting them back into place. "Nevermind, buddy, we'll fix that later. Now come on, we've lost so much time! We've got to go after that guy with the mask!"

Unable to stop the whirlwind that was Hiro Hamada with a mission, Baymax dutifully followed after him into the night. Left behind, invisible and asleep, Tadashi slept right through their departure, blissfully unaware of the dangers they would soon face.


AN: art for this chapter can be found at machina-rex on tumblr /post/106985287637/mochi-was-a-wonderful-pet-always-ready-to-curl

Please review and let Ikiracake and I know how you're liking the story so far!