Disclaimer: Naruto is property of Masashi Kishimoto, not me. However, Kosu and Hiro are mine. Warning, possible themes of a dark, violent or suggestive nature and use of mature language as the story progresses… They're ninja after all.

Chapter 9

Human race

Kosu chewed her thumbnail, eyes trained on the frowning boy across the table. Hiro had left his room. Thank Kami. But that was the extent of the progress. It was unnerving how close the walls seemed without his bubbly chatter to lighten the air.

"Hiro-"

"Thank you for the food." He mumbled, head tucked in and he quickly retreated into his room.

"Hiro!" She was met with the soft snap of the closing door. Kosu groaned, rubbing her palms forcefully against her forehead. Her stomach twisted as she placed her half empty plates on the side and gathered her ninja gear. She hesitated over the kunai leg bag, her eyes narrowed and she quickly strapped it to her thigh. Kakashi wasn't going to get an inch. They'd spent their first sparring session using no weapons. Their entire time at the academy had been no-weapons. The world isn't fucking no sharps.

Kosu hovered by Hiro's door, rapping her knuckle gently against it. Her ears easily picked up the shuffle of movement from within.

"I need to go Hiro." She said softly.

"… Bye." Sniffle. Kosu's fist clenched and she felt her chest turn hot and cold, tightening slowly around her heart. Slowly the soft, low sad notes of his flute came from within the room…

Hiro…

X

As was typical of Kosu, Kakashi didn't expect much conversation. They walked in silence from Kakashi's home to their training area. Still though. He glanced to Kosu, his body riddled with so much tension, a coiled spring on a hairpin trigger. Even for Kosu this was extreme.

"So you want to spar with weapons today?" Kakashi laced his hands lazily behind his head as they reached the training area. He turned to Kosu.

Eyes widened. He fumbled backwards in a clumsy attempt to avoid the slashing kunai. That's a yes.

Kosu welcomed the weight of a kunai in her hand once more, the sing of the metal as it cut through the air, only to be silenced as it slid across Kakashi's blocking arm. Kakashi measured his distance, backing away from her. She watched as he ran his hand down his arm. Shallow. Just a graze. Her mouth quirked at the corner as he took off his diamond patterned scarf and threw it to the side. He been caught off guard in their previous spar when she'd pulled it to set him up for a brutal takedown.

He narrowed his gaze on her, raising his own kunai in front of him. Isn't above a surprise attack. Not that he could complain. Kosu was one of the few who actively pushed him in spars. Something he never thought he'd be admitting to. Lateral thinking with experience was becoming an interesting challenge with her increasing skill to back it up.

Kosu dashed at him. Kunai flew past his right forcing him left and into the path of her sweeping kunai. Metal chimed as he met her kunai with his. Her brow furrowed, Kakashi slowly pushed her own blade back towards her. She snapped away from him, weaving beneath a swipe. A flick of his wrist and he repaid her for the cut earlier.

The pair met again, a wicked dance of flashing metal and glancing blows. Near misses and close strikes as they darted around each other, each constantly assessing and revaluating the changing situation. They jumped away from each other, panting heavily and covered in a multitude of small pink scratches. Blood that she'd managed to draw from him had been quickly repaid in kind. Small red spots scattered on the floor from both of them.

Settling her breath Kosu took in the entire scene before her. Swift hands pulled shuriken from her bag, and swifter still she palmed another to throw in their shadow. The hidden shuriken flew silently, barely above the ground. Kakashi jumped to avoid the arcing shuriken. Getting ready to release his own barrage with a smirk. His smirk fell. From below! He quickly had to defend from the surprise shuriken arcing up at him. The hidden shuriken hit one of her earlier kunai embedded in the ground and redirected straight at him.

Kosu pounced on his distracted state and tackled him out of the air. Her legs locked around his middle as she leant over him, kunai against his neck. Adrenaline danced behind her eyes.

"You're dead." She whispered.

"So are you." He smirked.

Kosu glanced down. Shit. Kunai to her stomach. Would this have been a real fight, Kakashi may have been haemorrhaging from his carotids but she would have been the idiot with her bowel hanging out.

With a sigh, she palmed the kunai from his neck and back into her leg bag. She unwrapped her legs from the borderline choke hold on his middle and flopped down beside him. The pair lay, panting heavily, staring at the sky surrounded by a debris of kunai and shuriken. Laying side by side Kosu's growth was more obvious. No longer was she the smallest member of her class.

Kakashi turned to look at Kosu, the hair pin trigger had been relaxed slightly. His jaw wasn't set so firmly and tight lines didn't seem to run through his body. Kakashi found himself smiling slightly.

"They're what you used aren't they?" He asked. Kosu turned, blinking in surprise when she found he was already looking at her. "Kunai and shuriken were what you used before." The way he handled them, how he kept track of every aspect of the fight, Kami, just some of the angles he achieved were impressive.

"Yeah." She nodded. How many times had it been her and nothing but a rusty kunai separating her from starvation… from death? Too many. "I'd have died a long time ago without them." She murmured. So quietly Kakashi would have sworn he didn't say anything if he couldn't actually see his lips moving.

"How did you get your first set?" Kakashi knew he was towing a fine line. Kosu had been with them for just over five weeks and he could count the number of thing he knew about him on his fingers. Personal questions were usually met with silence and an uncomfortable curl of the lip. Kosu's lip twitched, threatening to curl and Kakashi braced himself for another lengthy silence.

Her jaw clamped shut. She inhaled slowly and held his gaze. The tension left her jaw and she slowly exhaled. Kakashi's breath grew shallow as the hard mask Kosu wore seemed to soften.

"…They were left behind… by bandits… by ninja."

Kakashi's jaw slackened slightly. Kosu answered.

"I didn't take them at first." Kosu continued. Her fist clenched. How pathetic she'd been. "I didn't think I'd… I was so naïve… unprepared…" Her voice shook, almost growling with hatred at the girl in her memory. Never again. "I almost lost him because I was so clueless." Hiro's skeletal face flashed in her minds, sunken eyes, hallow cheeks… his rasping breath echoed in her head.

"It's hard to believe you were ever like that." Kakashi admitted. His gentle voice pulled her from her tumble into unwanted memories. She turned to him and blinked in surprise.

"Everyone is like that in the beginning. Anyone claiming otherwise is a liar." Kosu said. "But from there on out it's a race. A race for everything… for survival. You have to keep getting stronger and smarter or you'll fall behind." That's why you're not like them. Kakashi was already running whilst the others, the Konoha-sheep, were still strolling near the start.

Kosu's words were ominous but at the same time warmed his chest slightly. Too often with Kosu his words would be steeped in deeper meaning that only he seemed to be able to grasp. But for once, they were on the same level, a shared understanding between the pair.

"They-"

Kakashi yelped – actually yelped.

Kosu had palmed a kunai and slashed for his neck. It took a squirming reflex for Kakashi to avoid the glinting metal. Surprise attack again! He rolled to his feet as Kosu jumped to his. Their breath was back, their limps rested and they were ready to try to kill each other again.

X

Mito watched from her seat around the fire as Kosu approached. She was on time, but for someone who was constantly early, that was essentially late for her. Her intrigue peaked as the fire light revealed a criss-cross of fresh scratches marring her skin. Weapons sparring? Not two days ago Daiki had been jittery about her without weapons. No. Whatever that was, it wasn't academy.

Kosu sat wordlessly opposite Mito and pulled the scroll from her bag. She closed her eyes and focused on her chakra. It swept within her with perfect ease, washing around her body in soothing, warm waves. Whilst within her, control was there. Even as it coated the edge of her skin. The strain was there, the anchor weakening, but she could still move it to her will. It was as she tried to feed it into the paper that it discharged chaotically, red light flashing.

"Here."

Kosu looked up from her work and took the cup of tea from her sensei, inclining her head in thanks. Her sleeves rose as she reached, revealing yet more scratches. Mito made no effort to hide her examination of them.

"I see you've begun weapons training." Mito commented. Kosu eyed her over the top of her cup. She knows. Maybe not specifically where or with whom. She knows it's outside of the academy. Yet there was no anger behind her eyes, not like she would expect to see if Daiki found out.

Kosu nodded.

Mito's mouth quirked upwards and she took a sip if her tea. That was likely to be all Kosu would divulge.

"May I see?" Mito asked, gesturing to her scratched body. Kosu answered by pulling her baggy T-Shirt off and pulling her shorts up to reveal her thighs. They really went for each other. Mito inspected the scratches, some deeper and longer than others. But it was obvious that whomever Kosu was sparring with could toe the line between attacking with intent and being able to pull back just before a fatal slip. "I assume you've never received or likely seen medical ninjutsu before?" Mito asks, Kosu shook her head. She watched as Mito's hand glowed green. "It'll feel odd, but soothing." She assured as she laid her hands on the deeper cuts.

Kosu's eyes widened as she watched her skin knit closed. Chakra can do that? The same thing that flowed through her that she was so terrible at expelling could be used in such a miraculous way?

"There." Mito said. Kosu fixed her clothes and stared at her now smooth forearms.

Kakashi…

"That medical ninjutsu… Can Sakumo Hatake do it?" Kosu asked.

Mito blinked in surprise. She revealed her partner.

"Sakumo is a very talented ninja and that's a very basic technique. Kakashi will be well looked after." Mito assured. Kosu hid her small smile behind her cup of tea.

"We're training outside of the academy." Kosu said, watching Mito for her reaction. Her sensei merely smiled and nodded. "And going to go outside of the village to hunt." That caused a raised eyebrow from Mito. No teamwork eh, Daiki?

"Try not to almost get arrested again." Mito simply said. Kosu rolled her eyes and finished her tea, turning her attention back to the seal.

She ran her fingers over the coarse paper. That's the issue. Any attempt at channelling her chakra through the medium just ended in an uncontrolled flare of chakra. Kosu stared at her finger tips and then to the paper.

Mito watched with intrigue as Kosu charged each of her fingers with chakra and rapidly tried to tap each of the written kanji in order and timing. Her eyes widened as the briefest flicker of white broke through. It was faded and fleeting but most importantly is wasn't red!

Kosu stared at the paper in shock, her heart jumping in her chest. Chakra doesn't have to enter through the focal point of the seal. She covered the seal with her hands, making sure that every kanji was in contact with her skin. The pattern was well ingrained in her mind and by surging chakra at the right points of contact in the right order…

"Kosu."

She opened her eyes that had screwed up in strain and concentration. Beneath her hands a dull white glow. Her face was red and the veins bulged in her neck and forehead… But there it was… White. She let go of her chakra and gasped, sucking in big gulps of air.

Her breath levelled and her eyes focussed on the paper. Even pressing her fingers to the kanji, it was the paper she could barely control her chakra through. If it could just be removed…

She glanced to the ink brush then to her now healed arms. Her small hand wrapped around the brush, soaking it in ink. The tip hovered above her arm and she raised her eyes to Mito. Her sensei inclined her head, leaning forwards slightly, eyes alight. Kosu quickly began painting the kanji onto her forearm. When she was done she held it out for Mito to look at.

"This is completely your choice Kosu. You can walk away from this now if you wish." Mito said.

Kosu mouth quirked upwards. She knew the risks.

Kosu looked to her own arm. She could feel the chakra already there, thick and steady. Leaky vessels meant her entire body was soaked in chakra constantly. All she had to do was surge it at specific points on her skin.

"Oh Kami." Mito gasped, her face brightened by the glow of Kosu's forearm.

Kosu's jaw slackened before slowly pulling into a grin. No strain. Energy flowed rapidly and smoothly across her arm, spanning up to the surface to hit the kanji. The light faded as she relaxed her chakra and looked to Mito.

"You can use your body as the base." Mito all but whispered. Advanced fūinjutsu for a normal ninja. Her eyes slowly trailed over body until she met her gaze. But with her damaged anatomy… "May I try something?" Maybe… just maybe.

Kosu watched as Mito took a cloth and wiped the training seal from her. Her head tilted to the side as she watched her sensei paint the same kanji again but in a nonsensical order and across both forearms. She finished with the focal point of the seal on her left hand and sat back.

"You know the kanji, you know how they're supposed to weave and build together." Mito stated. Kosu nodded. "Learn where they are now." Mito could only watch as Kosu turned her attention to her arms. Her heart thumped against her chest. "No mistakes."

Kosu took her time. The lack of logical pattern made the symbols harder to remember but she looked back to Mito, confidence setting her jaw. Just what are you up to sensei?

"All fūinjutsu needs a medium to work through. The closer to nature the better as it's soaked in chakra, it's balanced. Fūinjutsu paper is the choice for most ninja." Mito explained. "Knowing this there are some fūinjutsu that use the central chakra reserve in the human body, a gathering of pure, even chakra, as a medium." Mito placed her hand over her stomach, the very medium she had used to cage Kurama. "You can use your entire body this way." Mito paused, she could practically see the thoughts firing behind Kosu's eyes. "I believe that by using your entire body, the kanji don't need to be written in order… you can weave that order internally, build the seal you want."

"It'd need to be perfect." Kosu murmured, eyes turning back to the kanji on her arms.

"Indeed." Mito took Kosu's chin in her hand gently. "I've never seen anything like this before, this is all theoretical." Kosu swallowed thickly and nodded.

She closed her eyes and took a deep breath. She could picture the seal she wanted to form, layered on top she pictured the arrangement of kanji on her arms, each one a piece of the whole picture. Chakra swelled within her and surged to the points on her skin.

Mito inhaled sharply.

Kosu snapped her eyes open. Holy shit. The focal point of the seal, the Uzumaki swirl on her left palm, was glowing so brightly she couldn't even see the ink.

Oh Kosu. Mito ran her hand over the young girl's short hair. Kosu stiffened beneath her touch before relaxing and leaning into her hand. The light from her palm faded.

Kosu's chest swelled with warmth and she felt it catch in her throat. All this time her body had been her weakness. All of their voices echoed in her head too small… not enough muscle… damaged chakra… And whilst they were correct, they were so wrong. Her body wasn't her weakness. She would make it her strength.

X

Kosu was sat at the table in their flat studying a tome Mito had given to her. Now that they had a technique to develop her knowledge of fūinjutsu and kanji had to be perfect. There could be no hesitation, no error. It had to be as much a part of her as her blood, her chakra. She glanced to her now bare forearms. That was how she would run the race.

"Kosu?" Hiro asked, head tilted to the side. "Why aren't you at the academy?" Kosu smiled and walked over to him, running her hand gently over his hair almost mirroring Mito. The academy… dead weight to run with.

"Hiro." She crouched in front of him. "Everything I'm doing is for you. To keep you safe. To keep you happy." She ran her thumb over his soft cheek. "I haven't been around as much and…" She sighed. "I'm around today."

"You're missing the academy for me?" He asked quietly, his voice cracking. She smiled weakly and stood up, ruffling his hair.

"What do you want to do today?" Kosu asked. Hiro sniffled loudly.

X

Daiki stared down, arms crossed over his chest. Kosu stood before him, patiently meeting his glare.

"You skipped lessons today." He stated. Kosu nodded. Daiki's jaw clenched. "Kosu you need an education if you stand any hope of being a good ninja."

Kosu stared back at him. Not from you. Not from being a Konoha-sheep in his flock.

Daiki sighed and pinched his brow.

"Where were you?" He asked.

"With my brother."

Daiki released his brow and paused the brewing rant.

"Is he okay?"

Kosu nodded. Daiki released his sigh and nodded.

"You at least showed to this." He uncrossed his arms. "Kosu you can't afford to fall behind, attending class is important." She bit back her retort. Hurry up and train.

Daiki paused, willing him to engage. Nothing. He motioned with his head and Kosu began the physical drills. In their first few weeks together he'd begun to see Kosu loosen up slightly, a hope that he would eventually move away from standing alone. Yet all that progress has dissipated in the blink of an eye.

X

Hiruzen inhaled through his pipe, analytical eyes watched the tense interaction between Kosu and Daiki. Daiki's shoulders slumped and he dismissed Kosu to begin the drills.

"He's done well to develop him to this point so quickly." Hiruzen commented.

"Indeed." Mito agreed. "But this is as far as he can take Kosu. They no longer suit as a Sensei-student pair." Hiruzen turned to Mito. Something's changed. "Hiruzen, this child has the potential to weld fūinjutsu the likes of which I've only dreamt of." His eyes widened at her claim. "He is wasted chasing arbitrary goals set by the academy. He has talent that can't be measure by their standards." She revealed a manila folder that had been hidden beneath the draped sleeve of her kimono.

Hiruzen took the file and opened it. He was greeted by Kosu's headshot, from the gaunt of his cheeks it was taken soon after he entered the Village. He's grown quickly. He moved to the text and his eyes widened at Mito's report. She's right. He glanced back to Kosu, now sparring with Daiki. They are unsuited.

"Mito-sama, are you asking to become Kosuke's sole sensei?" Hiruzen asked. Mito inhaled slowly.

"… No." Mito pursed her lips. Turn back the clock 30 years and she would have. "My days of physical combat are far behind me." He nodded, relief flooding him. Part of him doubted he would have been able to say no to her should she have asked to take Kosu on completely as her pupil.

Hiruzen inhaled from his pipe again and watched as Kosu darted around Daiki trying to use his speed against the goliath. Kosu was straddling the awkward grey area, but one thing was for certain. He was quickly outgrowing the academy.

Hiruzen turned from the window and pulled a thicker file from the top draw of his desk. Mito looked over his shoulder as the current shinobi team roster was spread out on the dark wood. He pointed to three familiar faces.

"They'll be broken up soon. He's needed as a jonin leader." Hiruzen pointed to the blonde. "If what you predicted of Kosuke's ability turns out to be true I think he'll be a good fit." Mito hummed her agreement.

"He'll be ready."

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So a bit deeper into Kosu's personality this chapter and BIG kunoichi developments for our little refugee! I hope you enjoyed the chapter!

XScouseLondonerX

BeyondItachi: Thank you for your review, so glad you like the story! Thanks for the info about Gai. He does have more ninjutsu prowess, but that's going to come a lot later in his development.

SnowCatt: Good suggestion! I grinned when I saw your review and can't wait to see what you think of this chapter.

Wyteeth: Thank you for your review. I completely agree. I'm not a fan of insta-romance and I feel like insta-friendship is also another more commonly overlooked issue. Whilst Kosu's barriers are slowly being chipped away at she's definitely still keeping herself well-guarded against those 'who aren't of benefit' for her. So glad you like Kosu! I hope you enjoyed this chapter.

Tabjoy13: Thank you! I hope you enjoyed this chapter.

Silverfoxkurama: Yay! Thank you for your review and I'm so glad that you like Kosu! She's definitely seen the darker side of life and has zero patience for the naïve brats in her class. Kakashi on the other hand… :D Hope you enjoyed the chapter… Saw a bit of a deeper side to Kosu this time!

Lizyeh2000: Thank you! No hospitals just yet! Mito's got her back.

TheWick: Thank you! Life was… well life and I had to prioritise other things. However I have Kosu's story planned out right through to the start of Boruto and I will tell it… it may take me a while … but I really want to tell her story. I hope you enjoyed the chapter.

May525: Yay! Thank you! Hope you enjoyed this chapter too!

Riv errr: Yo! Thank you! I really wanted to write the type of OC you see really rarely on here, and even more rarely in a Kakashi/OC! Hope you enjoyed this chapter too.

Curlystruggle: YAY! I'm so happy you're reading it. This chapter definitely went deeper into Kosu's psychology and revealed a lot more about her. Hope you enjoyed this chapter.

Slytherson: Snake are creepy af… not a big fan. Orochimaru never is a good sign! Hope you enjoyed this chapter.

Leeny len: Oh my god! Thank you so much! I'm back and as I mentioned above I have this story planned out right through to the start of Boruto… I really want to share it with you guys as well! I hope you enjoyed this chapter.

Hisui: Thank you for your review. Kosu is a complicated kid who's been through so much. For pretty much as long as she can remember it's just been her and Hiro and anyone they've encounter has either tried to use them/kill them. Her distrust of people is quite high. I hope this chapter reveals a bit more about why she thinks the way she does and why some people in the Village have managed to get closer to her than others.

To the Guest 28th: Thank you for your review. You raised some really good points. This chapter marks the beginning of a new chapter for Kosu so I hope you liked it a bit more. I'll admit that I'm not fond of an over powered protagonist (male or female) as I feel it lowers the stakes of the story. What's at stake when you know your protagonist can step in and wipe them all out? With respect to Kosu any flaw that she has is a result of her past and everything that has happened to her. Her flaws are as much a part of her as her strengths. I'm also a firm believer that flaws in one situation can be strengths in others and vice versa…

The children slipping past the guards was a plot hole I overlooked so well spotted!

I agree the children should be punished for sneaking away, but I feel like that punishment would have been done by their parents… that was my interpretation anyway.

Her secret is still safe!

OneWhoReadsTooMuch: (fantastic name) Thank you for your review! You picked up on a lot of the subtler points I made in the last chapter which makes me soooo happy! Kakashi is the only one who is even attempting to understand Kosu and that shows (and is rewarded) in this chapter. Orochimaru never is good news but I'm giving nothing away as to what his appearance hold for the future of the bothers!

HappyDog23006007341647: Thank you for your review! So glad you love my character and her actions! I really want to keep going!

NobodyInParticlr: :D Thank you so much! So lovely Kakashi-Kosu training in this chapter. Indeed! Orochimaru is a bad omen!

Hdmosprey: Thank you so much! It warms my heart whenever I hear a compliment on my OC! I hope you enjoyed this chapter.

Scarla Vanessa: Thank you, thank you, thank you! Such a kind review! My aim it to update more regularly! I hope you enjoyed this chapter :D as for writing advice… honestly, I got to this point by writing a lot and writing a lot of bad stuff as well haha. But most importantly, learning from what I was bad at.