Hey everyone, Poke'boy24 back with another new Story that I got the green light to do from my buddy on DeviantArt OrionPax09 who I'd like to thanks for giving my permission.

Now let to the Summary shall we…

Summary: Naruto has plenty of good intentions as well as a big mouth, now both those things are going to cause trouble when Tsunade's special project shows unexpected results.

Contains: Muscle/Breast Growth, Monster Transformation, Domination, Lemons, and Naruto x Harem.

Remember that Me and OrionPax09 DON'T own Naruto in any shape of form, because if I did, than I would have made Jiraiya give Naruto a heads up about Shizuka and her Village's Laws.

Now with no further delays, we both give you Naruto: Kinniku Kiss.

/ / / / /

"So… this is it, huh?" asked a 16-year-old boy with blue eyes, spiky sun-kissed blonde hair, whisker-like birthmarks on his face. He wore an orange and black jumpsuit and black headband around his head. As he spoke, he studied a vial of pinkish liquid he held in his hand. "The formula you and Tsunade-Oba-chan have been working on?"

"That's right, and please be careful with it Naruto!" pleaded a woman with short black hair and eyes. She wore a black-and-white kimono over a mesh shirt with a gray sash around her waist. As well as a concerned look on her face.

"Hey, I wasn't going to drop it or anything, especially not now!" Naruto exclaimed in a tone of wounded offense. "After all, today's the big day! Right Shizune?"

Naruto then looked at the other woman in the room. The second female had blonde hair tied in two short ponytails. She had brown eyes and a purple diamond-shaped marking on her forehead. She also wore gray sleeveless kimono which showed the proportion of her large G-cup bust, as well as a Blue sash around her waist, and dark-blue skintight pants.

"You know it!" Shizune exclaimed before placing her hands on her hips. "In a few minutes, you won't be able to call Lady Tsunade "Grandma" anymore!"

"That's assuming everything works as it should…" Tsunade muttered in an uncertain tone while crossing her arms, pushing her large breasts up making them look bigger. The top rank medical kunoichi and the 5th Hokage not looking anywhere near as happy as the others present.

"Huh? Is something wrong? I thought you would be really excited!" Naruto asked wondering why the Senju woman was down seeing as this would be her greatest achievement. "After all, you're about to be young again! You won't need that Henge anymore since you will have all those decades back!"

"Of course I'm happy Naruto, and not just for myself, but for everyone else that what we did could help them as well!" Tsunade declared proudly, body language betraying her as she looked down in shame. "It's just… this have never been done before. Everything we've been doing was experimental, and some of the research that we used…" she paused before closing her eyes. "…it was done by Orochimaru. So…"

"Oh, I see, you're a bit nervous huh?" Naruto asked while Tsunade was still looking down. "So… if you want to do more testing…"

"We can't Naruto! We've already used up most of the serum in the tests trials, and it will be a long time before we can make more!" Shizune explained. "That vial you're holding is all the serum we have left right now!"

"Besides… there really isn't any point as we've already learned as much as we can through small-scale testing. The only to proceed now… is by doing this." Tsunade grimly stated. "And since I'm the one who created this serum, I'm the only one with moral rights to be the test subject."

"Well, if you are sure… then okay. I'm ready to go whenever you are!" Naruto declared with determination before a questioning look appeared on his face. "I just… have a few questions."

"Oh? What are they?" Tsunade asked as she placed her hands on her hips.

"Well… are you sure that whatever this stuff does to me, it won't be permanent right?" the whiskered blonde asked as he questionably looked at the vial in his hand. "And… well… why do I need to kiss you in order for this to work? I get the part about me giving you some of my chakra! I get that! But still…" he paused as a small blush appeared on his face while rubbing the back of his head. "It's just that… I'm… really just not used to kissing, and…"

"Those are fair questions Naruto. In regards to the first one, we're positive that the effects will fade once the serum purged from you system," the younger woman reassured him. "As for the second… let's go over a quick summary of how the serum works," Shizune added, going into Professional mode. "You're already familiar with chakra right? That it's a mix of both physical and spiritual energy?"

"Yeah, I know all that! I'm not an idiot, okay?!" Naruto yelled back as he sweat-dropped. Remarks about his intelligence due to his poor Academy grades still a sore subject with him.

"Good, because that serum will temporarily alter your metabolism. Allowing you to create what Lady Tsunade and I have dubbed 'Heavy Chakra'," Shizune explained as she continued with her lecture. "This Heavy Chakra, when properly introduced into Lady Tsunade's own chakra system, will cause a cascade reaction throughout her whole body. The results will be a complete regeneration of all of her cells, restoring her to her youth."

"Okay, Heavy Chakra turns Granny Tsunade into Young Tsunade, I get that. But I still don't get the kissing part since there was nothing about that when I was helping you with the testing!" Naruto muttered crossing his arms and tilting his head. "Besides I just feel… weird, is all."

"I can understand about you feeling… awkward Naruto. I feel the same way as well. But our trial runs confirmed that this is the only visible option," Tsunade assured him before motioning to her student . "Shizune, if you would please explain?"

"Right! As you already know, we've confirmed that it will take a large quantity of Heavy Chakra to trigger the needed reaction. And you are the only one who can generate so much at one time." Shizune explained before pointing towards a diagram with a stick. "The problem Naruto, is that safely releasing so much into Lady Tsunade's system would be difficult for even a highly trained Medic-Nin, which you are not. So the only way this works is for you to generate the Heavy Chakra internally, and then pump it from your mouth into hers. There it will flow into her digestive system and chakra network where it will be processed on a physical and spiritual level, thus resulting in the needed cascaded reaction."

"Okay… I think I get it now. It's kinda like mouth-to-mouth!" Naruto asked looking at the serum with interest. "Only instead of air, I'm breathing Heavy Chakra into her! Is that it?"

"Heh, well that's close enough." Shizune said as an excited look appear on her face. "So are you ready to begin? Because I still have to give Lady Tsunade a full examination once this is over!"

But even as Shizune did her all to maintain a professional exterior, stars of excitement appeared in her eyes. 'Not only will Lady Tsunade be young again, but we're about to eradicate aging-related ailments and extend life by centuries!' she thought cheerfully as they stood on the verge of the biggest breakthrough in medical history. 'A Medical-Nin's dreams come true!'

"Hey, I'm ready whenever you are!" Naruto asked with a foxy grin. "So… I just swallow this and we're ready to go, right?"

"Right, and make sure you drink every last drop Naruto." Shizune assured him, at which the young ninja began downing the serum. "After which, you should start to feel the effects."

It wasn't long before the vial was emptied of serum. But as soon as it was drained, Naruto's eyes popped open. He gagged loudly, the vial falling from his hand even as his face drained of color and his knees buckled.

"Naruto! What is it?!" Shizune cried out in concern. "Are you alright?!"

"What happened?!" Tsunade fearfully demanded as Naruto visibly struggled to remain on his feet.. "What are your symptoms?! What hurts?!"

Shuddering, Naruto looked up to the two Medics, his face drained even as he gasped, "Erg… ugh… it… it… tastes terrible…!"

At this, Tsunade and Shizune sweat-dropped while the younger woman groaned. "Ugh… sorry!" Shizune winced as she recalled her own encounter with the vile taste of the serum. "I… guess I forgot to mention that." Shaking her head at her own absent-mindedness, the brunette focused her thoughts on the task at hand. "But… you better, well… you know."

Naruto nodded, but before he could make a move, Tsunade held up her hand in protest. "Wait, not yet!" she cried out in dismay. "I… there is one thing I…"

"WHAT?! NOW?!" Naruto growled in annoyance, a vein bulging from his head.

"Lady Tsunade?!" Shizune spat out in surprise. "But -!"

"It's not what you think! I'm ready! I…!" Tsunade began before her eyes fell to the floor. She started self-consciously rubbing her arm as she struggled to express what was bothering her. "I... it's just…"

As Tsunade struggled to find her voice, Naruto scowled and asked, "Just what?! What is it?"

Feeling a deep swell of shame in her heart, Tsunade thought back to the last man she had kissed fully on the lips. The lover whose life she had failed to save.'… Dan…'

Gulping down a lump of bile in her throat, Tsunade tried to speak her feelings, only for her voice to fail once more. "I… you see…" she tried once again, only for words to fail once more. Forcing her to voice a far lesser concern. "Once all of that Heavy Chakra starts flowing through my system… it's probably going to disrupt my Henge. And I don't want you to see me… like that."

"Oh, is that all?" Naruto asked, much to Tsunade's surprise. "Then I'll just keep my eyes closed while we do this! Oh, wait! Even better!" Then Naruto grinned broadly as he lowered his headband to cover his eyes. "There, and I won't take this off until we're done!"

This sweet gesture prompted a soft smile to appear upon Tsunade's face. "Thank you for indulging my vanity, Naruto." the busty blonde murmured as she took the young man before her in her arms. "Alright… let do this."

Tsunade pressed her lips upon Naruto's, and mere moments later, she could feel the Heavy Chakra pouring into her mouth and into her throat. From there, it wasn't long before the potent mix of energies made its way into her own chakra network, at which point the older woman felt her body shudder.

Grimacing even as Naruto continued to kiss her, Tsunade watched and felt as the sudden surge of Heavy Chakra disrupted her Henge, revealing the ugly truth she normally kept buried beneath the illusion.

The reality of an old woman that had been running from her past failures for decades. That had tried and failed to save the lives of both her brother and her lover. And had been punishing herself for these failures by slowly drowning herself in sake and gambling over the many years since she had left the Hidden Leaf Village.

But even as Tsunade was again questioning if she deserved this great gift, deserved to get back the many years she had squandered, the Heavy Chakra suffused her very cells. Reaching the critical mass needed to set off the required cascade reaction that was even now rushing through her body.

Within a matter of seconds, Tsunade could feel her cells rejuvenating. She could practically see the telomeres at the ends of every chain of DNA being repaired, as well as other forms of cellular degradation being reversed. She could feel her breasts and buttocks firming and swelling up. Feel tired old muscles becoming strong again, skin becoming toned, soft, and smooth and full of life.

And as the revitalization effect slammed into Tsunade, she forgot about everything else and became increasingly caught up in the heat of the moment. Old urges coming to the fore like a tidal wave, driving the revitalized woman to kiss the younger man with ever-increasing force. She pressed her chest harder into his own even as she raised her right leg and wrapped it around him.

In fact, both blondes were caught up in the heat of the moment that neither noticed the chakra crackling around their lips. Chakra that was building in intensity within moments. Right up until it reached critical mass, and…


A massive explosion of chakra erupted from both Naruto's and Tsunade's lips, sending them flying apart. The two of them trailing chakra from their mouths, they both slammed into the walls and hard. All the while Shizune reacted with shock and horror.

"Lady Tsunade?! Naruto?!" Shizune called out in a panic, looking from one to the other as she frantically tried to make sense of what had happened. "What happened?! Are you okay?!"

Pausing to shake her head clear of the stars and comets that resulted of the impact, Tsunade focused on Dan's niece. "I… I'm fine Shizune, just a little shaken is all," the Hokage stated, massaging the side of her head as she pushed herself back up. "Now go check on Naruto."

"A-Are you sure? That explosion…" Shizune continued to worry.

"Relax Shizune! As I said, I feel fine!" Tsunade urged the younger woman. But even as Shizune reluctantly heeded her orders, the blonde murmured, "In fact…"

With that, the busty Hokage rose to her feet. And with her mind cleared, she more thoroughly assessed her condition. Shifted about and studied her now younger body. "I feel better than fine! I – even when I was this young, I never felt this good!" Chuckling at their success, Tsunade continued to look herself over. "I feel… energized! More alive even! It's like -!"

Then a fresh surge of energy from within prompted Tsunade to gasp. A feeling that was quickly intensifying.

Meanwhile, Shizune was assisting Naruto in getting back up to his feet. "Relax, Shizune! I already told you that I'm okay!" the whiskered teen declared. "I feel… warm! Like I'm all revved up and ready for action!"

Shizune frowned in concern. True, there was nothing to indicate that Naruto was injured in anyway. If anything, his body seemed firmer, healthier. His jumpsuit seemed to hug his frame more tightly. And in theory, even if Naruto had been injured, the power of the Nine-Tailed Fox would already be healing any injury.

But even so, they were tampering with something completely experimental. And there had been nothing in any of their previous experiments that indicated that anything like this might happen.

"I'll be the judge of that, Naruto!" Shizune ultimately declared as she placed a hand on his arm. "Let's sit you down and give you a full examination!" Then she started to turn her gaze elsewhere. "You too Lady Tsuna-!"

Then Shizune looked at her mentor. And immediately forgot about everything else as she cried out, "LADY TSUNADE?!"

As both Shizune and Naruto looked on, they witnessed Tsunade's body quaking with increasing force. "S-Something's wrong! H-Heart pounding… b-body feeling t-too hot! Blood… feels like it's on fire!" she groaned, announcing her symptoms to the only other available Medic-Nin. "C-Chakra levels… rising too f-fast, s-so intense! L-Like I'm g-going to… t-to… ?!

An instant later, Tsunade's already ample bust swelled tremendously.

"EXPLODE?!" the exceedingly busty Hokage cried out in shock. Which was all she had time to say as further changes wracked her body.

Tsunade groaned in protest as the uncontrolled cascade reaction continued to remake her body. Her breasts continued to swell as her skin slowly stretched, giving way to bulges of muscle that there filling up her arms. Her blood continued to race and her breath came out in ragged pants as she shifted about unsteadily. She gave an involuntary flex of her arms, prompting her biceps up to swell and rise up proudly.

The air was filled with the sound of Tsunade's bones creaking and her flesh surging larger. Her buttocks grew as steely masses of muscle pressed up against the fabric of her pants. There was a distinct snapping sound as her sandals started breaking apart, her feet growing as her pants grew tighter.

Tsunade's breasts swelled mightily within her top, overflowing their fabric constraints. It wasn't long before the inevitable happened, and the front of the blonde's shirt exploded. "AAAAAUUUUUUUUGGGGHHHHHHHH!" the expanding Hokage cried out even as her mammoth mammary mountains danced and swayed proudly before her. "I'M GROWING OUT OF MY CLOTHES!"

As if in confirmation of her words, Tsunade's clothes were soon further ravaged by her increasing height and bulk. As her muscles throbbed and pulsed, building themselves up larger and larger, the back of her top split right down the center. Her sandals exploded completed, while the helm of her pants burst apart at the sides, revealing her tremendous thighs. Soon her shapely buttocks followed suite, splitting the back of her pants open.

As her clothes continued to disintegrate, being reduced to tiny scraps of fabric, Tsunade felt a grin splitting her face. Once again, the energies driving her transformation shoved aside her fears and concerns. A small blush appeared on her face as she moaned in ecstasy. Ecstasy she hadn't felt in decades, she yelled out in shock as she watched as her clothes were torn to shred by her growing height and bulk.

As her clothes were being reduced to tiny pieces of fabric, a small blush appeared upon her face as she continued to grow. "Ooohh… aaaahhh… AAAAAHHHH!... Hmm… YES!... ooohhhhh YEEESSSSSSSSSSS! ! !" the blonde Hokage moaned in pleasure, please that the energy coursing through her body was driving to new heights. "Ah… HA AH! Ah… ahhh… AAAAHHHHHHHH! ! !" she cried out as she felt something she hadn't felt in so many years. "RRAAAAAAAAARRRRRGGGHHHHH! ! !"

Tsunade let out a roar of pleasure as a very powerful orgasm rocked her body, causing whatever remaining bits of clothing to explode off of her body. This left her completely naked save for the dark-purple thong which was now soaked by years of pent-up juices.

"Huff… huff… whew! T-That was… intense!" Tsunade panted as she slowly came down from her high. "Whatever happened, it sure felt… amazing! Definitely worth one ripped up… AAAAAAAAHHHHHHHHHHH! ! !"

It was at this moment that Tsunade looked down at herself. And she realized that she was not only naked, but completely transformed. She had grown much taller, so tall that both Naruto and Shizune were face-to-face with her now firmer and larger L-cup breasts that were bolstered by her massive pecs. Her figure was a well-balanced mix of sturdy and curvy with an hourglass frame of her new massive melons, slim waist with a tightly toned 6-pack abs, and wide toned childbearing hips with a well-toned rear to match. With her whole body now sculpted with toned, hard muscles making her look like the Amazons of legend.

"What it the… just how much bigger did I get?!" Tsunade demanded as she looked down at herself.

"Uh… Shizune, that… wasn't supposed to happen… right?" Naruto asked as he stared at the transformed Hokage with wide white eyes.

"ACK!" was Shizune's only respond as she also stared at her sensei with the same shocked eyes as her jaw hung open.

"Um… that's a 'no', right?" Naruto asked.

"ACK!" Shizune repeated.

"That's definitely a no." Naruto added, realizing that this was going to be a long day.

/ / / / /

And there's the first chapter, and once again I would like to thank OrionPax09 for giving me permission to do this.

Take care and stay safe! ;D