Can the Rasengan really be "thrown"?
Absolutely!
Don't you remember in the original Naruto storyline, after intense training, Uzumaki Naruto was able to "throw" even the super difficult Wind Release: Rasenshuriken?
And in the movie version of the original story, Boruto: Naruto the Movie, didn't Naruto's son, the grandson of the Fourth Hokage, also manage to "throw" the Rasengan?
So, after mastering the Rasengan through accelerated training with the app, Koshino took advantage of the Fourth Hokage's absence, as he was guiding Kakashi, to restore his chakra and prepare for advanced Rasengan training.
"I never thought that completing the Rasengan training with the app would enhance my chakra control so much."
"If we follow Uzumaki Naruto's training from the original story, the next step in chakra control training should be changing one's chakra nature, right?"
"The Nara Clan's secret techniques have been passed down for so long, and transforming internal chakra into Yin Release chakra isn't very difficult.
Unfortunately, I haven't even tested my chakra nature yet, so training in chakra nature transformation is impossible. I can't just ask Minato-sensei for chakra nature test paper, can I?"
"So, I can only delve deeper into Rasengan training, enriching my arsenal while honing my chakra control!"
After analyzing the situation, Koshino, having restored his chakra, decided not to train in "throwing" the Rasengan but to focus on deeper Rasengan training.
What does deeper Rasengan training entail?
It must be the Big Ball Rasengan, not the Wind Release: Rasenshuriken! Not to mention whether Koshino's chakra nature is Wind, he hasn't completed chakra nature transformation training, so mastering the Wind Release: Rasenshuriken is impossible.
Settling for the next best thing, he prepared to train in the Big Ball Rasengan.
While Kakashi was still in the first stage of Rasengan training, Koshino, using his insights, perfectly executed the Rasengan with his right hand.
Then, to further enhance his control over the Rasengan, Koshino attempted to use a Rasengan with his left hand simultaneously.
By gradually accumulating experience this way, Koshino's chakra control ability would undoubtedly improve, laying a solid foundation for Big Ball Rasengan training, right?
However, using Rasengan with both hands simultaneously is far more challenging than using it with one hand!
Originally, Koshino thought he was more skilled than Uzumaki Naruto, able to use the Rasengan single-handedly without the help of shadow clones, so using it with both hands shouldn't be difficult, right?
Who would have thought that as soon as the chakra gathered in his left hand, there was a loud "bang"!
Koshino failed to control the chakra properly, and the Rasengan in his left hand exploded, blasting him away!
"Interesting!"
"What's the point of training if it's not challenging?"
"Alright, let's try again!"
Perseverance is an essential mindset in training.
Moreover, Koshino trained with Guy, and the pain of training with Guy was far more severe than the current pain.
So, after dusting himself off, Koshino prepared to use the Multi Shadow Clone Jutsu to aid his training. As for whether the secret of shadow clone training would be exposed to the Fourth Hokage or Kakashi, that wasn't Koshino's concern.
The Fourth Hokage was Koshino's teacher, and Kakashi was his senior. Was there any need to worry so much?
Besides, the shadow clone training method was originally Kakashi's creation, so Koshino felt there was no problem even if it was exposed early!
However, just as Koshino was about to use shadow clones for training, the app suddenly notified him that a new jutsu had been added to the training progress bar, catching Koshino's attention.
In a hurry, he checked the app's training progress bar, and to his surprise, he saw something.
He saw a new ninjutsu called "Double Rasengan" added to the app's training progress bar, and the training progress was already at 30/100!
"The app's accelerated training function is getting stronger!"
"The training of Double Rasengan has barely scratched the surface, not even grasping the essence, yet it's already considered part of the training progress?"
"If that's the case, then I really don't need to exert myself for advanced Rasengan training and chakra control training! With the app's effect, my strength can make a 'qualitative' leap in just one day!"
In his excitement, Koshino didn't hesitate for a moment and directly modified the training progress of Double Rasengan, successfully mastering the new ninjutsu.
And as the Double Rasengan training was completed, Koshino's chakra control ability undoubtedly became stronger. After all, using Rasengan with both hands is more challenging than using it with one hand!
Next, inspired by the Double Rasengan training, Koshino took a deep breath and prepared for the next stage of training, which was precisely the "throwing" of the Rasengan that the Fourth Hokage and Kakashi had witnessed.
To "throw" the Rasengan requires exceptionally strong chakra control!
However, since Koshino had already mastered the Double Rasengan, his chakra control ability was already strong.
So, on his first attempt to "throw" the Rasengan, he successfully threw it about half a meter away, and when it hit the tree trunk in front, the Rasengan's power didn't diminish, causing the sturdy tree to collapse to the ground with a loud crash!
"Indeed, as long as a jutsu is initially mastered, the app's training progress will record the training progress of that jutsu!"
"Rasengan Throwing Technique, huh?"
"It's a fitting name, just a bit unpleasant to hear!"
Just as Kakashi had completed the first stage of Rasengan training, the Rasengan Throwing Technique had already entered Koshino's training progress, with the progress directly at 50/100.
Silently modifying the training progress, Koshino perfectly mastered the Rasengan Throwing Technique, further enhancing his chakra control ability.
But as Koshino prepared for subsequent training, he caught sight of the astonished looks from the Fourth Hokage and Kakashi out of the corner of his eye, making him scratch his head in embarrassment.
"There's trouble!"
"Completely immersed in the thrill of the app's accelerated training, I forgot that Minato-sensei and Kakashi are still nearby."
"Letting them see my rapid training progress, won't that cause problems?"
Feeling a bit anxious, Koshino didn't know how to react other than scratching his head and grinning foolishly.
However, it was the Fourth Hokage who, in the midst of Kakashi's shock and Koshino's nervousness, gave Koshino a way out.
Unfortunately, when Koshino accepted this way out, he didn't feel any joy, especially when he glanced at Kakashi, feeling that his troubles were only growing!
"Koshino, your training speed is really beyond my expectations."
"So, after you finish training, go with Kakashi to meet your squad members and prepare to carry out a few simple missions!"
Don't forget them stones :DD