Maybe Sasuke teaches him the Chidori in a moment of camaraderie. And for the Rasengan, it could be an older and wiser Naruto from the future who travels back in time to teach his younger self.
The Naruto learns Rasengan fanfic can take the story in various directions. One direction could be a more in - depth exploration of the Rasengan's origin within the context of the fanfic. Another could be a time - travel plot where Naruto goes back in time and teaches his younger self how to learn Rasengan faster. It might also focus on the emotional turmoil Naruto goes through when he struggles to learn the jutsu, especially if he feels like he's letting down his village or his teacher Jiraiya.
One factor that makes a 'Naruto Learns Rasengan Fanfic' great is the ability to add new elements to the story. Instead of just repeating what happened in the anime or manga, it could introduce new challenges for Naruto. Maybe there's a new enemy who is also after the Rasengan's secrets, and Naruto has to learn it quickly to defend against them. Additionally, the fanfic should have a good pacing. It shouldn't rush through Naruto's learning process but also shouldn't drag it out too long.
In many fanfictions, Naruto might master the Rasengan through intense and unique training methods. Maybe he gets some special guidance from an unexpected source, like a hidden shinobi in the village who has a different perspective on chakra control. This person could show Naruto some new ways to focus his chakra, which finally enables him to form the Rasengan successfully.
In some fanfictions, Kakashi could also play a role. He is very knowledgeable and has seen the Rasengan in action. He might offer some tips on chakra control, which is crucial for Naruto to master the Rasengan.
One possible consequence is that he might become more confident earlier. With the Rasengan in his arsenal sooner, he could face opponents more bravely in the early stages of his ninja journey. This newfound power could also make him a target for stronger enemies who see him as a potential threat.
One creative version could be where Naruto learns Rasengan in a dream realm. In this fanfiction, the dream realm has unique chakra rules. He meets a mysterious sage who teaches him a faster way to form the Rasengan. Another could be a time - travel fanfic where Naruto goes back in time and learns Rasengan from his father. It gives a whole new perspective on the jutsu and his family connection. And there could also be a version where Naruto learns Rasengan from an enemy turned ally, which shows his ability to find common ground even with foes.
One possible plot could be that Naruto discovers an ancient scroll that has a simplified version of the Rasengan technique. He spends days secretly practicing it in the forest, facing initial failures but gradually getting the hang of it. With his new - found skill, he surprises his friends and even manages to use it in a sparring match against Sasuke, changing the dynamics of their rivalry early on.
The key element is Naruto's determination. He has to be really determined to learn both the Rasengan, a powerful chakra - based attack, and the Hiraishin, a complex space - time ninjutsu. Without that strong will, he wouldn't be able to endure the tough training.
It could be Kakashi. Since he's already Naruto's teacher and he knows both techniques. He could guide Naruto in understanding the intricacies of the Chidori, like how to form the lightning - chakra in his hand, and for the Rasengan, he could give more advanced tips on chakra control.