"As expected, he can use Nine-Tails Chakra at will." Jiraiya nodded, "Release it."
After Yuta returned to normal, Jiraiya continued, "What I'm going to teach you two brothers is a Ninjutsu called the Summoning Technique. The Summoning Technique is an interdimensional Ninjutsu where you form a blood contract with a creature and summon it to help you when needed."
"Wow, that's so cool!" Naruto's eyes sparkled, "Can you teach me that move? Really?"
"Of course, I'll give you two a demonstration first." Jiraiya bit his left thumb and slid it across his right hand.
Boar - Dog - Rooster - Monkey - Ram.
Jiraiya pressed his blood-stained right hand on the ground, "Summoning Technique!"
"Boom!"
The smoke dispersed, and the red-skinned toad that had been crouching in the grass appeared at Jiraiya's feet. He motioned for the toad to hand the scroll it was holding with its tongue to the two of them. Jiraiya then said, "This is the blood contract scroll passed down through generations. Write your names in blood on it, then leave five handprints together. The hand sign sequence for the Summoning Technique is Boar - Dog - Rooster - Monkey - Ram. Yuta, you try first."
Yuta opened the scroll, wrote his name, and left his handprints. While the blood hadn't solidified, Yuta mimicked Jiraiya, smearing a bloodstain on his left hand.
Boar - Dog - Rooster - Monkey - Ram.
"Summoning Technique!"
"Boom!"
A blue-skinned toad, similar in size to the red-skinned toad, appeared next to Yuta.
"Just a toad of this size has already consumed most of my Chakra. It seems that for now, summoning a Gamabunta-level one can only be done through Kurama," Yuta thought to himself, looking at the toad.
"I didn't expect him to be able to use the Summoning Technique so smoothly without using Nine-Tails Chakra." Jiraiya looked at Yuta in surprise, "This kid really has a lot of talent."
"Wow! So cool! I'll try too." With that, Naruto bit his finger and left his name and handprint on the contract scroll.
"Boar - Dog - Rooster - Monkey - Ram."
"Boom."
A ridiculously small puff of smoke erupted, and the three of them stared intently at the smoke.
"Plop... plop... plop..."
A tadpole struggled painfully on the ground.
"The difference is too great, isn't it?" Naruto looked frantically at the constantly hopping tadpole on the ground.
Jiraiya helplessly covered his forehead, "I thought Naruto would be able to use the Summoning Technique as smoothly as Yuta. It seems he still needs the help of Nine-Tails Chakra."
Jiraiya said, "Kid, first use up all your Chakra, then try again."
"If I use up all my Chakra, won't I be even less likely to succeed?" Naruto asked, confused.
"Just do as I tell you, kid. Don't you want to learn anymore?" Jiraiya pretended to reach for the scroll, "If that's the case, I'll erase your name."
"No, no, no!" Naruto quickly hugged the scroll to his chest, "I'll use my Chakra right now."
Naruto had witnessed the power of the Summoning Technique firsthand. This was the best chance to surpass Sasuke.
"Multiple Shadow Clone Jutsu!"
Naruto began a rather ungraceful brawl between his main body and his Shadow Clones.
Half an hour later... "Ha... whew... ha... it's finally over." Naruto lay on the ground, bruised and swollen.
Jiraiya walked over to Naruto with a complex expression.
This kid... is a bit simple-minded, isn't he? Doesn't it hurt?
Jiraiya said, "Now you try."
Boar - Dog - Rooster - Monkey - Ram.
"Boom!"
"Plop... plop... plop..."
"Why is it still you!" Naruto looked at the tadpole, on the verge of collapse.
Jiraiya turned his head, unable to watch, "This kid hasn't fully utilized his talent at all."
"I don't believe it! Summoning Technique!"
"Ah! Why is it still you!"
"Summoning Technique!"
"Get away from me!"
"Summoning Technique!"
"Ah ah ah ah!"
...Ultimately, Naruto ended his first day of training with a tadpole.
The next day.
A large tadpole.
The third day.
A tadpole with legs.
The sixth day.
A tadpole with four limbs.
The thirteenth day.
The tadpole's tail disappeared.
The twenty-sixth day.
"Ah!" Naruto looked frustratedly at the small toad on the ground, which was good for nothing but disgusting people. "I'd rather keep practicing Rasengan than this."
"Rasengan? You know about Rasengan?" Jiraiya, who had been peeking at the beautiful women around, turned his head in a daze.
"You know about Rasengan too?" Hearing this news, Naruto excitedly ran to Jiraiya, "Pervy Sage, you're so strong, can you teach me how to train the Rasengan?"
"Wait, is the Rasengan you're talking about this kind of Rasengan?" Jiraiya's right hand gathered Chakra into a blue Chakra ball.
Naruto nodded, "Yes, that's it. Since Pervy Sage, you can use this Ninjutsu, you must be able to teach me how to master it quickly, right?"
"Let's not talk about training for now." Jiraiya dispersed the Rasengan and asked curiously, "Who taught you this Ninjutsu?"
Naruto said, "Yuta taught me, about two years ago."
"Two years ago?" Jiraiya asked, confused. Currently, it seemed only he and Kakashi could use the Rasengan, but Kakashi hadn't even met the two of them two years ago, let alone taught Yuta a Ninjutsu of that level.
"Could it be that this kid developed it himself? Minato's inspiration came from the Tailed Beast Ball, so where did Yuta's inspiration come from?" Jiraiya put his doubts aside. He could ask Yuta about this tomorrow. The current focus was Naruto's training.
"So, to what extent have you mastered the Rasengan now?" Jiraiya asked.
Naruto didn't speak, quickly rubbing his right hand over his left.
"Buzz."
Chakra gradually converged into a spherical shape. Naruto held the Rasengan and said, "I reached this point about a month after I started learning the Rasengan, but no matter what, I can't make the Chakra more solid or sustain it for longer."
Jiraiya asked with interest, "You've already reached the third step of learning the Rasengan. How are you training now?"
Naruto took a balloon out of his pocket, blew it up, placed it on his hand, and then repeated the actions he had just used for the Rasengan.
"Boom!"
A large amount of Chakra instantly burst the balloon.
"That's how it is. Yuta said that as long as I can use the Rasengan without breaking the balloon, it counts as successful training." Naruto scratched his cheek in frustration, "I'm stuck at the last part. Pervy Sage, do you have any shortcuts?"
"There are no shortcuts in Ninjutsu training. However, since you want to train the Rasengan, then train the Rasengan in the morning and the Summoning Technique in the afternoon. You must master one of them before the Chunin Exams. Keep up the good work, young man." Jiraiya sat back in his rocking chair, "Keep training!"
"Got it..." Naruto replied weakly.
"Summoning Technique!"
...At night, Naruto, exhausted from a day of training, returned home. During dinner, Naruto mentioned to Yuta that Jiraiya also knew the Rasengan.
Yuta asked, confused, "Bro, you still can't use the Rasengan?"
Naruto said, frustrated, "Yeah, I can't solidify or maintain it."
That's not right. Bro has been learning the Rasengan for a long time, and he learned the Shadow Clone several months ago. How could he not be able to use the Rasengan?
Wait... Holy crap!
Yuta slapped his forehead. He had forgotten to tell Naruto such an important thing.
Yuta said to Naruto with a slight embarrassment, "Bro, releasing the Rasengan requires several steps. First, you need to release Chakra, then solidify it, and finally maintain it. This requires multitasking, even three tasks at once. But Bro, you have a shortcut you can take. How about... you try the Shadow Clone?"
How do I explain why Kakashi didn't take care of Naruto when he was little?
The early setting was that Naruto was the Nine-Tailed Fox's incarnation, so it's understandable that Kakashi didn't want to get involved with the Nine-Tailed. But the later original work added the Jinchuriki setting... I'm going crazy...