The Professor’s Student’s Student

Hentai Shinobi Rule 16: Being flexible is one thing; allowing the legendary Futa Jutsu into your harem is another. Only one cock stays in your harem—yours. Of course, use Futa Jutsu if you're into it.

***

Tsunade's body froze near the hospital's reception momentarily when she saw a familiar figure enter. She promptly schooled her expression. The blonde hadn't met Kai since she offered him a reward. It's been 11 days. So, Tsunade had time to read several journals and scrolls compiled by the many administration-funded researchers and doctors in the hospital's basement level and beyond.

So, Tsunade eventually discovered an intriguing topic.

You see, the reason why iryo-ninjutsu had legs to stand on was also the cause of its diversification and difficulty in compiling generalized jutsu like the Mystic Hands—Chakra.

Chakra interacted differently with every cell, kekkei genkai, mind, and spirit. In extreme cases, Chakra emboldened and bolstered the physical body. In other cases, it had a significant impact on the growing minds. Some become eccentric or even mentally unstable! So, now Tsunade rightfully blamed her gambling addiction on her greatest asset, her tits—ehm, chakra. After all, Tsunade looked for external things to blame her vices on.

Oh, she's a drunk? That's her grandfather's fault. Why did the man have to drink in her presence during dinners?

She's obnoxious? Blame it on her two stupid friends. Jiraiya was always a pain in the ass, and Orochimaru was too smart and sassy.

And now, Tsunade had another excuse.

Like her, Tsunade identified Kai as someone who fell in the latter category of innate chakra interactions. However, Chakra probably began with the boy's hormonal cycles this time. Or maybe he was someone who got a taste of both sides—physical and meta-physical? After all, no boy should be that thick when hard. Tsunade hurriedly vanquished the thought. Still, she was a woman of her word most of the time. She eluded about Orochimaru answering Kai's queries and intended to keep that promise.

It's not like Orochimaru acted reluctant once Tsunade revealed who would be his apprentice for a day.

Appreciating talents was common in their profession. Tsunade also knew how Jiraiya began keeping tabs on the other genius in Kai's classroom—a Namikaze.

"Good morning." the boy spoke politely, surprising Tsunade.

Where was that snobbish flair of his? She blinked before questioning. Tsunade was always blunt.

"Good morning? Did you hit your head or something? Where's the harem-chan who ogled at every other woman?"

Tsunade was mostly relieved Jiraiya did not pay more attention to Kai. The last thing Tsunade wanted was for Kushina's and her guardian to turn into a massive pervert.

Wait. The boy wanted a harem.

He was a lost cause from the beginning.

Tsunade shook her head as Kai smiled.

"I thought a lot about what you told me. Well. If I'm being honest, I only thought about it for a few seconds."

And there was that snob, Tsunade scoffed.

"So, I'm trying to be better than I already am," Kai's smile widened. "Now I'm going to just screw around with other bullies or ass hats instead of being one."

Who would have thought being rational with resurging emotions would unlock the legendary skill—empathy? Kai was often subjected to kindness by Mito. Even Tsunade didn't skim… on things. So, Kai didn't take long to realize his method of bullying orphans to prepare for the world was flawed. That's the only reason he stopped. Kai discovered a flaw and fixed it. Instead, he should have equipped the orphans with kunai, shurikens, and other weapons and tossed them in pits with their bullies and enemies to even things out!

Kai was rationally unhinged!

Jokes aside, Kai began to reign in his acts even if he had moments of screwing around with other kids. However, Kai did not tease others this time to teach their existence a lesson. He was just having fun and paid for the damages. That's how he usually spent his pocket money—enjoyment, a worthy cause in Kai's book.

Oh, and aside from empathy, Kai nutted relentlessly against 'Tsunade's' face, so there was also that—

For training!

Grind needed exceptionally-minded individuals!

Tsunade observed Kai with a narrowed gaze. Yeah. She wasn't buying what Kai tried to feed her.

"Whatever," the blonde huffed. "Follow me. I'll take you to meet Orochi. He's fun to hang out with once you look beyond his condescending nature when he talks about anything he knows more than you. Ah. He's like you. You two should get along just fine."

Kai walked beside Tsunade.

"So, he's the strongest amongst you and Jiraiya?"

Tsunade shook her head.

"Most knowledgable sounds right since he spends all his free time researching whatever he fancies the most. But the strongest…" She scowled. "Look. All I know is I punch the hardest. And that's all you need."

"The Academy failed you in various ways for you to utter such words," Kai concluded as he walked.

Tsunade snorted but didn't stoop to a kid's level for an argument.

"I was the best in the academy!" Tsunade couldn't hold the urge to rebuke.

"Oh, probably because I wasn't in the same classroom," Kai hummed nonchalantly as a vein popped over Tsunade's temple.

*Pah*

Kai almost fell face-first by the sudden, painful force against the top of his head before he glared at the woman.

"What?" Tsunade raised an eyebrow… and a fist.

A wise and rational man submitted to the circumstances, so Kai scoffed and didn't repeat his words. How's he ever going to get a harem if he irritates the most incredible and peak female specimens? That was illogical.

They silently continued down the halls before walking down the stairs into the underground levels. The antiseptic smell thinned at this level.

Working up the courage, Kai looked at Tsunade.

"Can I ask you something?"

"Orochimaru can clear all your doubts," Tsunade shrugged. "Why not wait?"

"It's not about theories." Kai worked his jaw. "It's…" He stopped in his tracks and cupped his chin. The thoughtful look on the boy's face almost made Tsunade squeak at how cute he looked. But of course, Kai had to speak and ruin that for her.

"Are you in a relationship with anyone else after what happened with Dan?"

"Just take a syringe and stab me in the heart, why don't you?" Tsunade's shoulders sagged as she listlessly groaned. "Why do you wanna know, kid?"

Tsunade had an idea why he wanted to know.

Kai tilted his head.

"I wanted to understand the competition."

Tsunade facepalmed herself before looking around. Seeing no inquisitive researcher around, Tsunade eyed the boy and ended things before they spiraled.

"Look, Kai." She began—

"Please," Kai shook his head. "I just want to know if someone is as willing to put in the work as me."

Tsunade blinked. She gestured to Kai to continue.

Kai had thought about this for a while. Sure, wanking off was fun. However, he read many works concluding that being direct was the best way to deal with such matters. It was respectful to the other party.

So, he did. Kai never lacked the courage or insanity to follow through with his plans. Age didn't matter. It wasn't like he was here asking for the best sex of his life. He was only here to understand if there was any hope in the first place. He would undoubtedly lose all his chances should Tsunade find someone remotely suitable without considering what she could get in a few years at best.

"Uh, I would like you to consider being in my harem."

See? Kai checked things out by being thoughtful and direct before crashlanding in all forms of execution.

Kai needed to grind his rizz. [Gamer Mind] and [Gamer Body] drained his Charisma Stat to the negatives.

Tsunade watched the boy in a daze before speaking.

"Was that it?" She tilted her head.

'I don't know. I never thought I'd get to this point.' Kai noted Tsunade's curiosity. She wasn't taking Kai for a chump and laughing right away.

"No," Kai cleared his throat. He got a chance to take off again and refused to crash! He recollected his thoughts before ignoring the sudden social pressure on his shoulders birthed from his lack of any attachments in his previous life.

"There are only a few things I won't do to achieve my goals," Kai straightened his back. "So, consider me as a worthwhile candidate for your future. Of course, I'm not talking about now but the future."

Tsunade appraised the little man before grinning cattily.

"Tell you what," she walked closer, towering over the youth. Kai barely looked intimidated by the difference. "Get two chicks on board, and we'll see."

"What?" Kai never expected such a response.

"I can see you want me to treat you like a man despite being a brat," Tsunade smirked. "So, here I am, offering you a realizable goal. You need to start with two women to kick off a harem, right? Achieve this much, and we'll both know you're serious. That's how a man announces his desires—through his actions."

Tsunade rested her hand on the boy's head, grinning Cheshirely. "And also grow taller. Remember, I'm not telling you to perv on girls and invade their privacies when I ask you to prove your desires with your actions. That's just harassment. However, you're a smart one, right? You understand what I'm talking about."

"Two girls?" Kai repeated.

"And you'll get an in," Tsunade shrugged. "When you're older, of course."

"Wait, I have another question," Kai began. "Are there any limitations on how I persuade someone into my harem?"

"Yep. Only voluntary ones count. Involuntary ones will land you in a world of hurt. Oh, and no money will be involved. So, chicks on the streets are off the limits."

Kai nodded.

"And can I continue massaging you until then?"

Tsunade froze.

"What?"

"Well, I suppose I can offer my services when Mito-sama is busy with Nawaki." Kai grinned.

Tsunade blanked out before snorting. "You aren't as innocent as you look, pervy-chan. See that door? That's Orochimaru's office. He knows about your arrival, so don't make him late."

Kai exhaled before shrugging. "I had to try. Still, thank you for not dismissing my concerns."

Tsunade watched Kai knock on the doors before leaving. Of course, she turned around the corner before crouching with a depressed look.

'Just where has my life fallen? Am I making deals with kids? He's 8! He'll take years to grow. Didn't I just admit I don't have what it takes to keep a man around by humoring the kid?'

Tsunade almost shed a tear.

Why do relationships have to be so complex?

Getting a good lay is the easiest thing in the shinobi village. Fuck! She could probably use a clone. However, Tsunade craved an excellent man and connection. Why would Tsunade ever lower her value by sniffing around Konoha's streets? She didn't look down on others who did, but she simply did not want to follow that practice.

Besides, most of the shinobi who craved a satisfactory lay were either weary from their missions or were about to leave one and feared they might die. Tsunade never had such concerns. Even her grandfather, the God of Shinobi, died. So, Tsunade never feared the inevitable.

"Oh, Rikudo!" She planted her face in her hands. "I just realized that Kai would objectively be better in this stuff if he could juggle two women, and I couldn't keep one man!"

She wallowed in self-pity for a few minutes before standing up and straightening her skirt.

'Whatever. A harem, huh? I should read on it and understand if there are any pitfalls in such relationships.'

Tsunade was always a nerd in her heart.

<<<>>>

"Oh, welcome, Kai-Kun."

A raspy, throaty voice greeted the boy once he entered through the unlocked door. Kai's gaze traveled around the room. It was a decently sized office with two cluttered desks occupying most of the space. Several documents, scrolls, and sheets lay strewn across, with a pale, dark-haired man leaning on one side of the joint desks, placing his other hand on the whiteboard.

"Let's begin. I heard you have questioned about Chakra's nature and its limits around the Transformation Jutsu."

Orochimaru's no-nonsense policy was more appreciated than Kai let on as he obediently took one of the chairs and began.

"I wanted to know why the Transformation Jutsu can allow us to mimic the physical qualities of our targets but not anything else. We can even mimic our target's body odor with enough skills."

Orochimaru's pale, yellow, slitted eyes brightened as he nodded.

"You will be surprised by how little shinobi in the village ask such questions. The answers lie in the existence of chakra. Tell me, Alpha-kun. What is Chakra?"

Kai almost choked on his spit before scowling at the amused cunt.

"Chakra is the mixture of physical and spiritual energy," Kai answered.

"It's an incomplete answer taught in the academy. I'm afraid the complete answer is its own can of worms that no teacher would like to put their students through."

Orochimaru chuckled and drew a perfect image of a man in a meditative position before drawing two inter-connected semi-circles in the man's torso. With that, Orochimaru pointed at the circle.

"This is Chakra. As you answered, it's the mixture of spiritual and physical energy. However, there has been a misconception since before the warring era that spiritual and physical energy mixing in an unspecified ratio makes our chakra. I'm afraid that's wrong. Yes, our spiritual mind and physical energy nourish Chakra. Yet, Chakra is its own realm. It is beyond what our minds and bodies can create. For instance, why doesn't everyone hope to be a shinobi if everyone has chakra? Would it not be a child's play to train and grow our chakra? If so, what's stopping us from growing our chakra endlessly? Why are there more mediocre shinobi than the elites?"

Kai inadvertently thought of the limits on his stats.

Orochimaru continued.

"Why do we have chakra coils if we only needed our bodies and minds? Won't our circulatory system suffice?"

"So," Orochimaru smiled. "The first step in answering your question is to remove your misconceptions about chakra."

Kai nodded. The skills he had also informed Kai about chakra. However, his trait offered knowledge of Chakra's application instead of its origin and nature.

"I understand," Kai spoke. "Chakra is another source of strength aside from physical and spiritual energies. It just happens to have a positive, nourishing cycle with these two."

Orochimaru smirked. "Very good. The second step in answering your question is to enlighten you about how chakra acts within our bodies. You see, like everything in life, Chakra has its limits. I'm afraid these limits are genetic. Ah, I'm getting ahead of myself. Genetics are—"

"What dad pumps into mum to create a kid," Kai scowled. "I know. No wonder Tsunade-san said you were condescending."

Orochimaru shrugged. "I do things my way, Kai-kun. Let's continue. When I say limits, I don't want to discourage you from believing hard work and discipline do not play a role in our growth. It's the opposite. Anybody with the talents of a shinobi and enough training will see themselves becoming respectable in our society. However, most lose their motivation once progress is barred by months, if not years, of consistency."

"Our Chakra grows with our training. It has more to do with our connection with the world's Chakra and not our spiritual and physical growth. If anything, our growing chakra significantly improves our mind and body."

"World's Chakra?"

Kai perked up. He had heard of this topic.

"Yes," Orochimaru revealed. "It's simple once you think about it. How does our Chakra recover?"

"By resting."

"And are you aware of the limits on our Chakra?"

Kai hesitated before shaking his head.

"Have you heard of tales about a Shinobi becoming a powerhouse for mere moments to save the lives of his comrades or his loved ones? There are other tales about mothers displaying monstrous strength as they overturn carts to protect their children from getting overrun."

"Some kids have no survivor's instincts," Kai scoffed.

"Indeed. Yet, it's not the point I'm trying to make." Orochimaru exhaled before marking eight dots on the drawn figure.

"Chakra is interlinked with our bodies. When you exhaust your chakra, you aren't bottoming out every bit of the chakra present. You merely use the Chakra available. Ordinarily, it's 20% of your entire chakra reserves."

Kai's eyes widened. He did NOT know that.

However, he instantly realized the truth.

"It's like how our bodies consume most calories just to function. What we lose through exercises is a fraction of what our body burns through daily."

"Very good," delight danced in Orochimaru's eyes. "You are correct. Exhausting our entire reserves will spell our deaths because whether we like it or not, Chakra is symbiotic, and our Chakra Coils ensure that everything about Chakra seeps into every tiny corner of our body. Our bodies regenerate chakra through resting, eating, and nurturing our minds. However, Chakra follows the several familiar rules of conversion."

"We aren't creating Chakra," Kai whispered in realization. "We disperse and regain it."

Orochimaru's gaze brightened.

"And where do we disperse and regain our Chakra from?" Orochimaru grinned.

"Our surroundings," Kai fell silent before looking at Orochimaru. "Is our planet… alive?"

"As far as planets go, yes. A dead planet could not hope to create life," Orochi smirked. "Our world has its Chakra network. Are you aware of sensors, Kai-kun?"

Kai nodded.

"Sensors are Shinobi with a sixth sense for this Chakra Network. They can tap into it and locate other sources of connected Chakra from long distances without any expenses. Congratulations. Now, you know the basics of Chakra. You are now also privy to how chakra acts in our bodies."

Kai grew silent. These revelations broadened Kai's horizons as he could finally form several conjectures and theories.

"So, we cannot copy chakra-related skills from a Transformation Jutsu due to our chakra coils. Genetics must impact chakra coils if they also cap a shinobi's upper limits. Meaning—Kekkei Genkai isn't all about the blood in our bodies but Chakra itself. If that's the case, the only way to perfectly transform into someone would be by thoroughly studying and mimicking their chakra coils."

Kai grew into the topic as he dazedly looked at the table.

"I'm missing something," he mumbled. "It cannot be easy, or Kekkei Genkai wouldn't be a thing. Chakra Coils… World's Chakra…"

Kai's gaze brightened.

Orochimaru waited and let Kai think things through.

"Symbiosis?" Kai glimpsed. "What did you mean we have a symbiotic relationship with Chakra?"

Orochimaru grinned.

"I meant, we have a symbiotic relationship with the World's Chakra network. Chakra is a power that creates lineages of Kekkei Genkai. Chakra is as physical as it is metaphysical. We cannot copy Kekkei Genkai merely for these reasons. I'm afraid you were overthinking things. The world's Chakra network has nothing to do with it. They simply exist everywhere in nature. And it's a symbiotic relationship because we aren't completely dependent on Chakra as seen with others who don't have the talents for possessing massive chakra reserves."

Kai sighed. It was probably true. He might be overthinking it.

"Maybe the method of copying Kekkei Genkai is known to everyone," the boy snickered. "It's the process that stumps everyone."

Orochimaru chuckled.

"That's the truth."

"So?" Kai questioned. "Why do we have the talent and others don't?"

Orochimaru smiled. "I'm afraid we must rack our brains about it sometime else. Now, you may leave."

"Wait," Kai frowned. "I was told I could be here for the day."

"Because that's how much time an ordinary 8-year-old would need to process this information."

"Can't I stay and see what you're researching?" Kai looked around. "I won't disturb you."

Orochimaru would doubt another boy's words. However, he chuckled.

"Very well. Anything on the table is off-limits. See that shelf? The scrolls on the upper right section are yours to peruse."

"Thanks," Kai grinned and sat in the corner.

The duo did not talk. However, Kai noted how Orochimaru had to leave twice. Any other boy would believe Orochimaru left to get lunch and dinner. However, Kai keenly observed Orochimaru's legs briefly trembling.

'A disease?' Kai mused but didn't pry. Orochimaru already did Kai a favor by steering him in the right direction.

'Maybe I will access this World's Chakra network with enough [Perception].'

***

Alternate Title: Tsunade's a Nerd; Nerd Alert; Tsunade: It's That Damn Chakra's Fault; Studious; Kai Got The Chakra's Gift; Chakra Be Like: Here's a Thick D. Go Bang Away; Tsunade's Idle Thoughts; The Direct Approach; Polite?; Kai Unlocked Empathy Bruh; Kai: Now, I'm An Asshole For Fun. Yay~; Kai Evolved; Growing To Be A Harem Lord; Tsunade Steers The Boy Right; 2 Girls?; Kushina and Mikoto In The Distance: We're About To End Tsunade's Whole Career; Kai Nutted Away; Kai Ain't Taking Any Chances; Cobra Kai: Strike First, Strike Hard *Kai's Cobra: Happy Noises*; Tsunade Is The Rizzless One; Kai Can Cook, Clean, And Massage; Throwing In The Hat; Consider Me; Kai Took a Shot For Massage; Tsunade's Smarter Than To Fall For Kid's Words; Depressed Tsunade; Existential Crisis Hits Tsunade Harder Than Mito's Stick; Orochi's Office; The Discussion; A Favored Student; Woah, Exposition; The Underlying Source of Chakra; Kai: The World's Alive? *Starts Fisting Ground*; Overthinking; Even The Best of us Sometimes Overthink; A Pleased Snake; Orochi Sus; Sensors' Secret; Tsunade: Don't Be a Pervert To Have a Harem *Also Realizes Libido and Perversion is Necessary For Harem*; Tsunade Digs an Orgy For Herself

***

Join the discord through the link in the synopsis.

Read 15 chapters ahead @ Patron and Subscribe Star (Links in the synopsis.)

Support the Fanfic through comments, likes, reviews and such (if the published site allows it.)