"To begin with, the fireball jutsu is a simple jutsu. You expel fire release chakra from the tenketsu in your throat after coating its insides with a layer of chakra."
"That simple?" Haruto asked with his eyes narrowed in suspicion.
"Yes. But before we begin with the jutsu, we must make sure that you can protect your throat well, if not then you'll end up in the village hospital with burns stretching down your throat."
Haruto shivered involuntarily simply by imagining the scenario.
"How do I make sure I do that?"
"Hmm… Let's start with something simpler. Let's start with coating your palm in chakra to withstand the heat of your flames, then we can move onto your throat."
"Makes sense… but I don't think I can keep the chakra outside my body from escaping, I don't have the chakra control for that, is that alright?"
Hiruzen laughed softly, "What made you think only high chakra control allows you to keep your chakra outside your body for long?"
"Are there other methods? How?" Haruto asked with a little surprise.
"Simple, to begin with, create your chakra with a lot of spiritual energy and very little physical energy, that will give you a high level of control over it. That's how beginners learn the jutsu. Give it a try."
Haruto's eyes widened, "You can do that?", and he asked with surprise.
"I know. I know." Hiruzen nodded calmly, "I know you want to ask me then what's the point of the balanced set up? If there is such an easy way to improve your chakra control, why not simply use this imbalanced kind of chakra all the time? Right?"
Haruto nodded as if the words had been pulled right out of his mouth.
"Why don't we try it out right now?" Hiruzen asked calmly with his hands folded and looking right at Haruto.
"Try it out?"
"Yeah, try using the imbalanced chakra to perform the same thing you did earlier, shooting out a small fire from your palm."
"Alright…" Haruto frowned but closed his eyes nonetheless and focused on trying to create this new sort of imbalanced chakra.
It took him only a few seconds, about half a minute, to create a small amount of the imbalanced spiritual energy chakra. Curiously the new chakra didn't merge with the old one, as if it were a separate entity acting completely independently.
He passed it through the tenketsu in his solar plexus before holding his palm out like before.
"Here goes nothing…" Haruto mumbled as he slowly released a small amount of the imbalanced chakra gathered in his palm.
There was a small puff before fire radiated outwards from his palm once again, however Haruto's eyes were narrowed, "It's not really hot at all."
"Precisely." Hiruzen nodded, "If you'd have done the same with the physical energy, the fire would've turned hotter but would've been much harder to control. This is why balanced chakra is very important, it allows you to exercise control over your jutsu while also giving you a balanced physical effect."
"I see…" Haruto nodded, his mind already spinning gears with new ideas. 'So in a pinch if I want to blow up my enemy, I can use physical energy dominant chakra?'
Hiruzen's gaze sharpened as if seeing through Haruto's ideas, he nodded and explained, "It is a good idea to try to use physical energy charged chakra in case of a pinch. But for your level it will be extremely hard to control, which means you'll only end up blowing yourself up before your enemy."
Haruto's eyes widened again, he nodded.
"Alright then, try coating your hand with some of that spiritual energy charged chakra."
Haruto nodded one final time and focused on using the spiritually charged chakra to coat his hand. He expelled the chakra through the tenketsu in his palm and quickly controlled the chakra to wrap around his palm.
Except this time unlike when he'd tried it out in the comfort of his home, the chakra flowed much smoother, almost like a docile fish, completely wrapping around his hand like he'd dipped it in water.
'A dark silvery shade of blue…' Haruto observed the colour of his chakra, something he hadn't been able to do before.
"That's about right." Hiruzen said softly, moving closer to inspect Haruto's hand before nodding. 'He's definitely better than Jiraya was when he'd started learning the fire release jutsu I taught him… only goes to show that the right crucible can produce the best talents.'
"Try coating your throat next, then we can move onto the fireball part."
Haruto closed his eyes and focused inwards.
He hadn't tried expelling chakra through other tenketsu yet, and pin pointing a tenketsu inside his body was turning difficult since he couldn't visually see or feel the spot given his entire circulation system was filled with chakra.
Luckily for him, Hiruzen noticed his problem and placed his hands above the rough area for his throat tenketsu.
Haruto accepted the guidance gracefully and figured out where his tenketsu was and slowly released chakra through the tenketsu at the base of his throat.
It took a while even with the spiritually charged chakra, but Haruto quickly managed to coat his entire throat in the special chakra.
"I think I did it…" Haruto nodded, feeling a slimy sensation in and around his throat as his chakra clung to its insides like a film wrap.
"You sure?" Hiruzen asked with his one visible eyebrow raised in question.
Haruto simply spoke with a frown, "I think so…"
Hiruzen immediately smirked.
"Well then! Let's get to it! What better way than to try out the first fire ball!! Make sure to use little chakra and make sure to release it quickly."
Haruto closed his eyes softly, guiding the more balanced chakra in his body towards the solar plexus, gathering fire nature chakra at the tenketsu at the base of his throat before opening his eyes sharply and exhaling quickly through his wide open mouth.
"HA!!!"
Haruto expelled all the fire nature chakra in his throat all at once, shouting simultaneously while doing so to ease his nerves.
Haruto's eyes widened as a stream of fire poured out of his mouth, coalescing into a three meter large fire ball in front of him while flying towards Hiruzen.
"Kakashi-san!!!" Haruto shouted in worry since the fire ball was extremely hot.
He felt the hair on his eyebrows singe slightly but cared not for it as his eyes remained perfectly on Kakashi!
Hiruzen only smirked lightly, "Don't worry about me Haruto-kun! I'm not in ANBU for nothing."
With but a single handseal, Hiruzen slammed the ground with his foot causing a slight tremor to fill the training ground before an Earth wall rose up between him and the fireball!
However, Haruto quickly noticed something off about the wall.
'Didn't Kakashi have his earth wall embellished with dog heads?'
But there was no time for Haruto to pursue the thought.
"BBBBOOOOOOOOOOOOOOMMMMMMMMMMMMMMMMMMMMM!!!!!!!!!!!!!!"
A short explosion rang the training ground area, kicking up dust and smoke all around causing Megumin in Haruto's mind to cheer!
'Explossion!!!!'
'Woah!!! What are you doing you brat!! What's all that power fo-'
Edward's voice cut off at the end and Haruto felt a little worried for him, but at this moment his focus was on Kakashi as he watched through the gap between his fingers while shielding himself from the explosion.
The dust slowly settled and Haruto found himself staring at the same pristine wall that had risen up earlier.
'Not even a scratch?' Haruto was surprised, he nearly did a double take until he nodded to himself, 'Obviously Kakashi could tank that… otherwise how would he be a Jonin…'
On the other side Hiruzen began laughing, "Hahaha!!! That was magnificent! Haruto-kun, let's go through the motions again, this time with a little less spiritually charged chakra and more balanced chakra to see if you can still do it without burning your mouth! Eventually we'll work on the speed of your fireball and the explosion size!"
The wall crumpled away and Hiruzen became visible in his full form, completely unharmed and unspent.
Haruto's eyes shone with jealousy but he got to work nonetheless.