Summary: A 'what if' story about an innocent Tokiko without her scar and a cynical Kazuki with limited time.
Disclaimer: Buso Renkin doesn't belong to me. The original AU was by the prolific author The Sacred and the Profane.
Notes: Are all warriors only born when young and through great loss? Or can a young woman become the inner warrior she had bought so bitterly in another time? My apologies to The Sacred and the Profane for hopping on the AU bandwagon.
Buso Renkin: Reversal of Worlds
He stared up at the sky and tried to ignore the dried blood on his hands.
Why did you let her die?
While he tried to turn his mind to more important things, he ignored the odd and unfamiliar warm wetness that ran down his cheeks.
Tsumura Tokiko rarely dreamed. But when she did, she dreamed vividly.
The haunted factory? Why was she there? She froze as she heard an insidious sound. Something heavy and metal dragging across the floor but it was worse than that. She flattened against the wall and saw the shadow of something huge, something monstrous- And a boy. He was a student but she didn't recognize the uniform. Vivid blue gakuran left open with a white shirt underneath. It almost looked like Ginsei's uniform but-
Why was he walking like that, as though he had no cares in the world, when something horrible was stalking behind him? What was wrong with him?! She tried to quiet her breathing as she flattened herself against the dirty concrete wall. No- This had to be a dream. It was a nightmare… The shadow arched and poised to strike. No! She found herself running, screaming, "You idiot! Move it!"
Pain exploded in her chest and she stared dumbly at the spike that had run her straight through. The hot metallic smell of blood flooded her nose and she could taste it on her tongue. She couldn't breathe, couldn't move. Was this- death?
Tsumura Tokiko woke up screaming.
"Oi-i-i! Toki-chan!"
Tokiko extended her arm and let the blonde boy run into it. He reacted as predicted and went flying, easily clothes-lined. A vein throbbing somewhere in her forehead, she said testily, "I told you not to call me that."
Nakamura Gouta rubbed at his bruised nose. "Fine, fine. Tokiko-senpai," he said sarcastically, emphasizing the last title. He got to his feet and picked up his dropped school bag. "Why didn't you wait for me? And why are you carrying your elementary backpack?"
The vein continued to throb at Tokiko's temple. "I forgot," she said flatly, just to make Gouta face-fault. "And I can't find my school bag."
"Tokiko-san!" Both of them turned to face the newcomer, a petite girl with light brown hair pulled into two pigtails.
"Saori-san," Tokiko said politely.
"Ne, Tokiko-san. Are you all right? We heard screaming from your room last night," the other girl said anxiously.
"What were you doing?" Gouta asked suspiciously.
"Nothing. It was just a dream," Tokiko said, trying to slide the matter under the rug as quickly as possible.
"It must have been a scary dream," Saori observed. "What was it about?"
Tokiko rubbed a finger across the smooth skin on the bridge of her nose absently. "I pushed a boy out of the way of a monster in the old factory," she found herself saying quietly, recalling the dream through a comfortable fog. "He was an idiot anyways," she added with a grumble.
"Eeeh? Was he cute?" Saori giggled. "Did you save him?"
Tokiko shrugged. "I couldn't see his face completely. And I died," she said bluntly. "It hurt."
Saori and Gouta both face-faulted. "That's awful!" Gouta yelled. "What kind of a dream is that?!"
Tokiko shrugged again as they passed through the school gates.
"Tsumura," a deadpan voice said. "What are you doing without your proper school bag?" The emotionless English teacher came up and stared at them unblinkingly with his blank gray eyes. She could feel Gouta tense up slightly; Saori was smart enough to take a step backwards but she was shivering too.
Tokiko bowed her head slightly. "My apologies, Mita-sensei, I couldn't find it this morning."
Thin lips pursed a little. "Unacceptable. Report to the faculty room during break."
Some hours later…
Tokiko came to the roof where Gouta was waiting with his dearly bought school lunch. He tried to pass her one of his tonkatsu sandwiches but she refused, having her own bento for the day.
"What happened?" he asked worriedly.
"Detention," she replied flatly. "Weeding the back garden after school."
Gouta gaped. "What the hell is up with that?!"
She shrugged. "I lost my bag, after all." She opened up her bento and started to eat.
"I'll do it for you," he offered. "Or I can help you out." He had an unusually eager expression on his face for a boy who never cleaned his room until the dust bunnies were the size of German Shepherds.
She didn't bother to look at him. "No need. It won't take too long. You probably won't even have to save me dinner."
"But- I can walk you home at least!" he protested.
"No thanks."
"Please-" he wheedled.
"No."
"Tokiko-san, you're so mean to a man!"
"Be a man then." As he shrank in mortification in the background, little mushrooms popping about his head and shoulders, Tokiko pulled out her celllphone, realizing she had just gotten a text message.
Her eyes widened. The screen read, "Enjoy your new life." Her surprise soon subsided as she noticed a little smiley emoticon at the end of the message, which made her sweat-drop. What kind of person could have sent this? she thought to herself. Then she looked around furtively, though she didn't expect to see anyone there. Sighing softly, she closed her phone just as Gouta recovered.
"Tokiko-san, can you loan me your Japanese homework?"
A vein twitched in her temple. "Tell me how you passed the entrance exam?" she scolded.
He blushed and muttered, "I managed."
"With the lowest passing score," she growled. But she handed her notebook to him all the same.
Above, perched on the school's water tower, a young man closed his cellphone and smiled very slightly. Then his expression grew fierce. Where are you?
Tokiko was used to physical labor; she was hardly a delicate flower. Weeding was more tedious than actually backbreaking, after all. She dusted off her hands and surveyed her work, feeling sweat trickling down the back of her neck. Just a little more and she could go home and make something quick for dinner…
"Tsumura." She jumped as Mita-sensei came around the corner of one of the buildings. He tossed something familiar at her feet. A bag with a distinctive gear charm (Gouta had gotten it for her at a matsuri one year, against her rather loud wishes).
"My bag- where was it?" She went to pick it up but Mita's foot almost crushed her hand and she looked up at him in surprise.
A curious light was in his eyes and she had a bad feeling about the faint smile that was creasing his pale lips. "I found at the abandoned factory," he said, almost lightly. "When I was about to have dinner."
She found herself backing up a little and a flicker of memory flashed at the back of her mind. A horrific shadow along a concrete wall… the hissing of steam engines and a giant snake… "I wasn't-"
He advanced, his mouth seeming to open wider and wider with each word he spoke and his eyes starting to blaze red. "I killed you then. And yet you're alive. I must-" His voice became a sibilant hiss "-rectify this." And his body shook and shifted in a manner that no human had any right to change in, spikes erupting from his back and shoulders. A monstrous cobra reared, laughing in a hollow parody of Mita's emotionless voice.
She screamed and ran for her life, the monster racing after her. 'It's a dream!' she thought hysterically. 'It can't be- I'm dreaming again! Mita-sensei isn't that- that thing!' The chirping ring of her cell phone interrupted her hysterical thoughts and she grabbed it from her skirt pocket, answering it.
A young male's voice told her immediately, "Keep running. I'm on my way. Just give me three minutes!" His voice was urgent but quite collected and calm.
"Three minutes?! Who are you? What is that thing?" she screamed into her phone.
"I'll explain later. Just get out of the school. It's hard to talk and run at the same time."
"I want to know what that damn thing is!" she shrieked, so terrified that she dropped all honorifics and propriety.
"Long and the short- it's a homunculus. A monster created by alchemy, it looks like humans, acts like humans, and eats humans." Then he abruptly ended the call. She cursed vividly.
As she was running, she was getting to the front of the school, though she was going to be trapped by the construction they were doing to the wall if she wasn't careful- Then she almost ran into Gouta.
"Run, Gouta!" she screeched, shoving at him after skidding to a halt. "There's no time. Just get out of the way!"
Gouta stared like an idiot and she turned in time to hear the roar of the mechanical cobra. Time seemed to stall as she saw the huge links of the coils of the snake thud into view and the wedge-shaped head baring scythe fangs crash into the ground before her, swallowing Gouta whole. She stared dumbly as the cobra jerked his head once and bared his fangs at her once more. The scales shifted and an approximation of Mita's head and face emerged from the jaws.
"You cheated me of dinner," he said monotonously though a laugh started to bubble up at the end of his words. "Now I need a double helping."
White rage filled Tokiko's vision. She snatched up a pole from the construction site and charged at him, screaming. "Give him back!" she shrieked. "Spit him out! Give him back, you bastard!" Her vicious attack took him off guard for a few seconds and she thought she could see some headway into his scales. But he recovered quickly, withdrawing his head, and snapped her weapon in half.
"Silly little girl," he sneered. "Too weak to do anything. Only alchemy will hurt me."
She tried to wrench what was left of the pipe away even though the rage mingled with fear. She was going to die, she knew. And she couldn't protect Gouta-
Her vision blurred as a throbbing started in her chest. She tried to scream but could only release a choking noise as she clutched at her chest. Ah yes… a memory. She was staring at her corpse, eyes blank in a perpetual expression of surprised pain. And the same male voice that had called her was speaking to her.
"You died. You didn't understand the situation and you jumped in without thinking." That voice, it was so incredibly sad- It was heavy with guilt and pain. "It was my fault. You tried to save me. This is the least I can do for you."
A glitter of something in the moonlight. "Kakugane. The ultimate alloy regulated by gathering the essence of alchemy." He sounded like he was reciting something and the sadness never left his voice completely; if anything, it deepened. "It will activate by melding with your instincts, the deepest depths of a human mind. This will be a substitute for your heart and awaken your survival instincts. It will give you the strength to live again." Warmth filled her empty, cold chest and began to slowly and steadily beat. Ah… had she been without a heart? She never realized how much she needed it. "At the same time, you will have a new strength."
The last words were whispered, "You will gain another power through the human combat instinct, the power to fight. That is the true power of the Kakugane."
Her eyes opened again and she faced the cobra. A new strength filled her and pushed the fear away with a firm hand. Mita sneered again, "You should have been dead. I will make it that way!"
"Buso Renkin! Sunlight Heart!" There was the scream of sliced air molecules, a flash of red, and something snapping sharply in the wind. She stared at the blur of silver and red that resolved itself to a shining lance with a fluttering red scarf, held in the hand of a boy in a blue gakuran with wild dark hair.
"You! You were the one-" Cobra-Mita didn't have a chance as the boy charged at him, thrusting the lance forward and puncturing him in one smooth move. "It can't be! You were the one with the-" The boy twisted his lance and jerked it upwards, disemboweling the monster and sending metal bits flying everywhere. One strangled roar from the cobra-Mita and he disintegrated into nothing, leaving only Gouta, who started to fall to the ground before Tokiko ran over to grab him.
"Gouta!"
He was still breathing and didn't seem terribly hurt, to her immense relief. Once she made sure he was all right, she turned to the stranger.
He was a little taller than her and just a little gangly. His very dark brown hair stuck out in every direction but formed a zigzag series of bangs that almost hid his burgundy eyes. Under his gakuran, his white shirt had an odd design what looked like two lollipops over a western "w." A slightly goofy smile crossed his lips and creased the corners of his eyes. Tokiko had seen her share of smiles; his was warm, good-spirited and genuine, like sunlight, but something dark lingered in the depths of his eyes.
"I remember what happened," she told him. "I saw lights at the haunted factory and I went there- You were there, about to be eaten by Mita-"
"Nope," he replied a little sheepishly. "Sorry, but I was only acting as bait to draw him out."
Tokiko felt a flush of embarrassment fill her entire face. "I died because of a stupid mistake?!"
"Err… I guess we can put it that way," he said, flushing as well. "It was an honest mistake."
Gouta stirred in her arms. "Gouta!" she exclaimed but he didn't completely open his eyes.
"He's fine," the boy replied. "Nothing's wrong with him. He's probably better off than you."
She breathed in relief. "Good." She slowly got to her feet, supporting Gouta against her shoulder. Some made the mistake of thinking she was weaker just because she was petite and short; few made that mistake twice.
The boy was looking at her oddly. "You're an odd girl," he said bluntly. "You scream pretty loud, too."
A vein throbbed in her temple. "Forgive me if I've just been scared witless!" she snapped at him.
"But you're pretty strong." He smiled at her. "Brave too. You're interesting." The lance dissipated into a small series of glowing hexagons that hovered around him before reappearing as a hexagon in his palm.
At the infirmary, Tokiko found the dictionary after getting Gouta in a bed. "Alchemy," she read aloud.
"Scientific synthesis techniques that spread through Europe before the modern age," the boy quoted, coming up behind her. "The goal was to create the potion of immortality or to turn lead into gold. Even if they didn't succeed, they created the basis for modern science."
"But alchemy couldn't have created that- thing," Tokiko said, flustered. She wasn't sure whether it was from his close contact or from trying to reconcile something that came out of fantasy with real life. Her eyes went to the side and she almost thought she saw his face turn red before he jerked away from her.
"This is just a basic dictionary, isn't it?" the boy said with a shrug. His ears were a little red as he looked in the opposite direction. "In reality, there are two kinds of alchemy. The one you don't know about defines logic and resulted in the ultimate creation: Homunculi and Arms Alchemy."
"Homunculi? Arms Alchemy?"
"Homunculi are creatures from research in creating artificial life," he said and his voice became hard. "Arms Alchemy is from weapons development. Both were considered extremely dangerous and kept a secret from the world, except by those who mastered alchemy. But there are those who have escaped supervision… They are scattered all across the world and they hide, eating humans."
"The haunted factory," she murmured. The boy nodded and went to the window, which had a perfect view of the site.
"It's a base for the Homunculus," he said. "I got one. Now I have to get the rest. Buso Renkin." The lance materialized in his hand again and she realized how easily he held it, despite the fact it looked heavy enough to send him crashing to the ground.
"Wait- You can't go there alone," she blurted out. Her hand reached out to grab his shoulder, so she could shake some sense into him like Gouta- But she stopped in time, realizing just how rude that would be. Besides, this wasn't Gouta. This boy was something else entirely.
He smiled at her and she couldn't help but see that it held a great deal of sadness. "You can't. It's my responsibility as an Alchemist Warrior." He hesitated, and added, "I gave you the Kakugane that acts as your heart so you could live. I can't let you throw that away."
"Then why are you telling me all this?" she demanded.
"So you don't feel lost. And so you know what I'm facing so you can get away." His expression grew serious. "I've interrupted your life, your world already. Don't let me disrupt it anymore."
"But-" Gouta stirred and she shot an alarmed glance at her friend's direction.
"Battle is my mission," he murmured. "Please don't come," he said, a bit louder.
"But you're going alone!"
"Think of your friend," he told her. "You shouldn't leave him all confused, y'know..."
"He's already that way," she replied dryly and he politely sweat-dropped.
Then his expression darkened. "This is not much of a choice. You can stay here and have the life you still live. You won't have much of a life if you follow me. It's not a good life at all… it won't suit you." Despite his polite words, he didn't seem to be giving her any choice in the matter. She tried to protest by words died away from heir lips.
He opened the window, letting in a warm spring breeze laced with sakura petals. Then he offered her a faint but the most sincere smile she'd seen yet; somehow all the others seemed flat in comparison to this one. "Be safe, k?" And he vanished.
Gouta woke up a little later to find Tokiko staring right at him. He almost fell out of bed. "Tokiko-chan! Don't do that! It's freakin' scary!"
"Come on, let's go back. In fact, let's run there," she said with a rather ominous expression in her amber eyes as her mouth spread in something like a grin. One of Gouta's eyes twitched nervously.
"K-k?" he managed to say.
Some time later, Kouji found him on the front of the dorm complex. "Ow, ow, ow," Gouta was yelping in a steady stream, looking rather dazed while sprawled on the floor.
The glasses-wearing boy crouched on the ground next to him. "Gouta? I thought you were going to get Tokiko-san."
"Yeah- I did," Gouta said feebly. "Except she dropped me off here and said she forgot something at school. She ran off before I could say anything. Ow."
Kouji sweat-dropped. "I see."
"Don't just say 'I see'! Help me up!"
Kazuki slashed at yet another ape Homunculus, crushing it to bits. While it wasn't difficult to dispatch these low level monsters, they were starting to come at him in waves, climbing up the walls and leaping at him. If he wasn't careful, he'd be overwhelmed- The last one crumbled apart with one last slash and he was left in a desolate battlefield littered with rusting parts.
Panting, he looked around for the primary Homunculus with narrowed eyes. His black hair was even darker from sweat and the ends were drooping. A gruff, deep voice rumbled from the shadowed corners of the factory.
"So you're the Alchemic warrior." Saruwatari, a hulking tanned man in baggy green cargos and a skintight black wifebeater, stalked from the shadows, arms crossed. "You're better than I expected… but you were stupid enough to come in here alone, boy." His body started to shift in a way that never ceased to roil Kazuki's stomach, his muscles sliding way for geometric panels of metal that formed jagged stalagmites. Soon an immense mechanical gorilla towered over him, the man's upper body and head on the torso.
Kazuki smiled thinly and drew up his lance. Saruwatari roared, "I will crush you like a bug!"
The boy waited, ready to dart away at the last second as the immense fist came at him. But when he tried to reposition his feet, he couldn't.
"Saruwatari-sama! I've got him!" the remains of the smaller Homunculi buzzed, wrapped around Kazuki's ankles.
"Damn!" Kazuki lashed out with his lance, severing monkey's arms straight through. But this wasn't the only one that hid from under the bodies. They teemed up and grabbed him, pinning his arms too, seizing the cloth of Sunlight Heart and tangling it up.
"Trapped like the little insect you are!" the gorilla roared in triumph, fist coming closer.
A rusted side door burst in and a small girl in a yellow school uniform dashed through, tossing aside a brick. Both Saruwatari and Kazuki stared as she ran in, a fierce expression glowing in her amber eyes.
She reached at her heart and cried, "Buso Renkin!"
The boy's quiet, sad voice recited, "You will gain another power through the human combat instinct, the power to fight. That is the true power of the Kakugane. It gives form to the user's dormant power and will create a unique weapon. Grasp, resolve, roar. It's called…"
"Buso Renkin!" she shouted. Power filled her and sang. It coalesced around her legs, cool metal touching at her thighs but feeling lighter than air. Four blades hummed to life around her and launched her in the air. She leapt, feeling them respond to her very thoughts as they diced away the mechanical arms and torsos keeping the boy and his lance trapped. Then she leapt at the gorilla, who swiped at her. Her blades sliced his arm and he yelped as they gouged deep into his wrist. They retreated in time as he made to backhand her and she landed on the ground safely.
"So you had an ambush too," the gorilla-man growled. "Very good. But is she even remotely useful?"
Tokiko snarled silently and her blades helped her jump into the air. But this time he was ready and he snatched at them, threatening to crush the long scythe like blades. A wave of disoriented pain ran up her spine and she flinched, grabbing her chest. The other two blades were free though and they went for the unprotected torso. Her aim was off and they only glanced off, missing the projection of a human head and chest. She cursed as she tried to aim but he arched his torso away from her, protecting that vulnerable spot.
"Pierce, Sunlight Heart!" There was a flash of blinding light and a crunch of metal. She had a quick glance of the boy charging at an inhuman speed at the gorilla and the tip of his lance stabbing into the human head.
The face distorted and he managed one last horrible cry before the boy thrust completely through him. His momentum sent him nearly flying into the wall ahead but he turned at the last minute and kicked off it, landing safely on the ground. Tokiko wasn't so lucky or so graceful as the Homunculus collapsed in on itself, sending bits of metal flying everywhere. She yelped as she sailed through the air but her blades were ready for her. They flexed and spread, getting her straightened out and landing her safely on the ground. The boy had been trying to catch her as she screamed but he just missed being impaled through by one of the scythe-blades as it stabbed into the ground. He yelped, dancing back just in time.
"Are you all right, Tokiko-san?" he asked worriedly.
"Just fine," she wheezed, her heart feeling like it was beating far too fast. Eventually, the pain in her chest eased and she could breathe properly again. Her knees felt watery all of the sudden and she knew that the only thing keeping her up was her blades. Speaking of which… she eyed them with interest.
They were surprisingly elegant, gleaming silver chrome that were lovely in their stark simplicity except for some details of hexagons. She liked them instantly; they looked like scythes and scalpels. Experimentally, she stretched out her hand and the front right blade twitched and extended forward, making her skirt shift.
The boy jumped back, flushing. She glared at him. "I hope you weren't looking where I thought you were looking," she snapped. "Pervert."
"Not at all! I swear!" he babbled, turning red as his lance's scarf. He looked up and met her eyes solidly. Why hadn't she realized that his eyes were a curious shade of garnet red? "I thought I told you to go back with your friend!"
"I did," she informed him. "I dropped him off and ran back here. A thirty minute run."
"I didn't give you a choice!" he said, sounding almost angry. His eyes blazed for a moment but she couldn't care less.
"I didn't want one. I already knew what I had to do," she replied just as testily. She folded her arms. "Look, I care about Gouta. And you act just as stupidly as he does, so you need to be looked after just as much as him." She glared, sending him a wintery look through her amber eyes.
The boy jerked his head to one of the walls. "Look over there," he said.
She looked and blanched. Human bones, some crushed, but all of them picked clean and gleaming white under the dim light. Empty eye sockets stared at her; some of the bones seemed very small. "Kami-sama," she breathed, horrified.
"That's what they do. I think that this isn't their only base. Chances are there are even more of them in this town. My mission is to root them all out." He looked grim. "I'll let this slide for now but you can't follow me." His eyes looked to her and didn't quite plead but came very close.
"If there are these- Homunculi running around, Gouta's going to be in danger. My classmates are going to be in danger. So there's no choice in what I have to do. You gave me these." She gestured to the blades. "You can't expect me to stand by and do nothing. You can't expect me not to do something for those people." She gestured to the bones.
He looked at her steadily for a long moment then he made his lance disappear. She noticed that the motes of light that made it up faded into his chest rather than into a hexagon and wondered. "Come on," he said, offering a hand.
Tokiko paused, not sure about how to make her weapon disappear but even as the thought flickered through her mind, the blades disengaged from her legs and disintegrated into light motes that faded into her chest. He caught her as she started sagging to the ground and helped her walk out, to her embarrassed relief.
Once out in the sweet spring air, he said, "Sorry for… everything." He sounded very sincere despite his sheepish tone.
"I can't just stand aside," she told him, concentrating on walking as steadily as she could. "Not when you gave me the ability to fight these monsters. I'm going to help you eliminate them all," she said fiercely.
"Nothing I tell you is going to stop you, is it?" he said with tired laugh.
"Never."
"Right then." He propped her against a tree. His lance appeared in his hand and he pointed it at her. "I'm going to have to train you then, as an Alchemist warrior trainee. Promise me that you'll never die in front of my eyes again. Especially when you think you're going to save me!" Though he kept his tone light, a note of fierceness entered his voice at the command. "If you're going to tag along, you're going to have to listen to me. Got it?"
"Right." She grinned at him and then tilted her head. "By the way, what's your name?"
He flushed instantly, even under the moonlight. "Ah! I never did tell you, did I? How rude of me. It's Kazuki. Mutou Kazuki."
"I'm Tsumura Tokiko."
"Tokiko-san." And he smiled broadly at her.
Note: Why did I have Tokiko fail in killing Saruwatari? Because the Valkyrie Skirt isn't meant for very strong and high-endurance opponents, at least according to Wiki. I can see that happening, quite frankly. Though she would use her instincts, I don't think she would have had the ability to focus on his weaknesses and use her weapon to cut him to ribbons; her basic strength is in her ability to be quick, smooth and clean in her attacks.
A couple of notes on names:
"The Japanese name Kazuki may be written with the characters for "one" (kazu) and "timber trees; wood" (ki). Other possibilities include "harmony; Japanese style; peace; soften; Japan" (kazu) and "timber trees; wood" (ki), as well as "one" (kazu) and "radiance; shine; sparkle; gleam; twinkle" (ki)." –Quoted from an online babyname site.
I think that the last one is the most appropriate, no? "One Radiance" describes Kazuki pretty damn well.
Tokiko is most commonly known as "Child of Toki." "Toki" can be translated to "Full of Hope" or "Time of Opportunity." Not quite as appropriate, perhaps, but some apt points to be made about her.
According to the Wikipedia article, Tokiko was based on Hitokiri Battousai, of Watsuki's other famous series, Rurouni Kenshin, at least in appearance. Kazuki was based on Makimachi Misao. I decided to swap them just a little bit.
So how would Tokiko have turned out if she hadn't been the survivor of the school massacre? How would Kazuki be if he had been the Arms Alchemist first? I mulled about this for a while and came to a couple of conclusions.
1) Kazuki would be a cynic. I know that this is the antithesis of his basic character but I think that even the best optimist would be horrifically battered after the horrors of Alchemic training and missions. But- he wouldn't show his cynicism; he'd quietly acknowledge it, along with his hypocrisy, and paste a smile on his face, like Kenshin. He would figure it's easier to smile just a little and seem disarming, particularly in an attempt to somehow interact with the world he's forced to distance himself from and to try to live as much as he can as a human. Human life means a lot to Kazuki and he knows that he has the responsibility to protect human lives because he has the power to do so ("Great power comes with great responsibility" and all that jazz).
1a) Kazuki would still be the Victor, not Tokiko. It lends Kazuki's role reversal an interesting aspect, particularly when he ends up infected by a Homunculus. He knows he has a Black Kakugane in him, perhaps because someone let it slip, and that knowledge privy to only a few people, including Bravo, who gave it to him by accident when they first met. Kazuki can only stall for time before he becomes a Victor. He's looking for a cure but it's becoming more and more hopeless and he knows it, though he'll try to find the solution for as long as he can keep his humanity.
1b) Kazuki would still have his sister. She would not be an Alchemist but she would know about her big brother's secret. The organization helps to pay for her schooling at the Newton's Apple All Girls Academy (a good, relatively safe school that also keeps Kazuki compliant) and she's been trying to read up on Alchemy in an attempt to help him (even though science isn't her thing, period).
1c) Kazuki was saved as a child from a similar massacre as Tokiko. His sister escaped because she was sick that day at home. Bravo saved him just from the point of death; everybody else was eaten or killed in a subsequent landslide and Kazuki had been killed by being thrown against a pole or some other thing that pierced his heart and was left for dead by the Homunculus.
2) Tokiko would be just as sober as she is in the original story; I think that this is a basic aspect of her personality. I can't see her being incredibly silly as a child; polite and kind maybe but never as 'genki genki' as Kazuki is. I think she'd be more of a typical girl (and I hate myself for saying that) though just as brusque and bossy as her original form, as well as unwilling to let her best childhood friend Gouta (who not-so-secretly has a crush on her) to walk her home. Under the girliness, she has a backbone of pure steel, though most would consider that a bullheaded stubbornness, and a curious sense of justice. While she respects human life, she takes a pragmatic approach to serving others. Vengeance comes to her easier than saving people.
2a) Tokiko would get her distinctive facial scar eventually while becoming an alchemist warrior, at a very important point. She would refuse to get it healed "properly" of course and use it as a point of resolve for her, perhaps in saving Kazuki from his Victor side.
2b) Tokiko would be an orphan. Her parents set up an account for her, which is why she's able to go to a decent school, but otherwise, she has one relative who looks out for her but is unable to do much. Gouta would probably be the 'boy next door' who opted to go with her to a far away school and just barely got in through the entrance exams. Having no parents would maintain Tokiko's stoic personality and a certain determination to handle things by herself.
3) Kazuki would feel a lot of guilt about having Tokiko die which is why he would give her the Kakugane he happened to have with him. He wouldn't cry, not even in front of her corpse, but he would speak the words of the Kakugane and Alchemist Warrior's Code distantly to her as if reciting them, not out of admiration (these were probably the exact words Bravo told him when he was saved as well). Having someone killed on his mission, particularly a female, would be one of the worst things to happen to him and would damage him greatly. His words don't mark a good start to their relationship and would probably come back to haunt him or both of them.
4) Kazuki would train her but always would be holding back a little, to her frustrations. She would end up pinning him to a tree with her Valkyrie Skirt and scream at him, saying that how can she become stronger if he keeps being easy on her. Homunculi wouldn't show her mercy and he's sending her to be killed if he doesn't buck up and train her right. The parable of the butterfly and the boy would probably pop up, echoed by Chouno. Kazuki would smile, apologize and not hold back, leading her to comically come back with a lot of bruises, to the horror of her dormmates.
5) Bravo would be an undercover agent or an ex-Alchemist who quit because of his overwhelming guilt. He kept his Kakugane and because of its immense defensive abilities, he can use it to keep his identity hidden and to quietly protect wherever he's staying. Bravo probably trained Kazuki initially (and thus started his love of green vegetable juice) before leaving, and he also probably found Kazuki and gave him the Kakugane. He probably found out too late that the Kakugane was a disguised Black Kakugane and by that time had grown so attached to Kazuki he couldn't bear to kill him. So he trained Kazuki and told him what had happened as well as training him viciously to restrain the Black Kakugane under periods of great stress (if Kazuki couldn't control it, Bravo would have killed him himself). Bravo then left the organization and was never seen again. For some reason (most likely just because it's his personality), Kazuki has never been bitter and has reasoned that departure with, "Bravo had some sort of reason to leave. It wasn't me." But he would be just a little bewildered. In the mean time, as the dorm supervisor, Bravo would be keeping an eye on Gouta and Tokiko, particularly Tokiko because something about her reminds him about someone in his past, not to mention he finds himself charmed by this seemingly delicate, stoic girl who can easily kick most of the guys' butts.
These are my basic notes. Some details may change. The reason why I've put up these notes is to show my reasoning when I developed this storyline. I may end up writing more; I may just leave it at this. Look for the "Complete" status. For now, enjoy my mad thoughts and digressions.