It could be Orochimaru. Since Orochimaru has a long - standing feud with Jiraiya and is always up to no good. If Naruto ditches Jiraiya, Orochimaru might see this as an opportunity to manipulate Naruto. He could try to convince Naruto that Jiraiya was holding him back and that he can offer Naruto more power, all while having his own evil plans for Naruto.
One great fanfic could be about their adventures before Naruto was born. It might explore their relationship dynamics, how they trained together and supported each other. Maybe in this fanfic, Jiraiya tries to convince Tsunade to take on more dangerous missions with him, showing his trust in her abilities.
It could lead to Naruto becoming even stronger and more skilled than in the original story. Jiraiya's training methods might unlock new powers for him.
In many 'Naruto Jiraiya fanfiction' works, the relationship is explored through flashbacks. For example, Naruto might recall the times he spent training with Jiraiya, like how Jiraiya taught him the Rasengan. This helps to show the bond they had, with Jiraiya being a father figure to Naruto.
One popular theme is his relationship with Naruto. Many fanfics explore how he mentored Naruto, the lessons he taught him, and the bond they shared. Another theme is his travels. Since Jiraiya was a wanderer, fanfics often detail his adventures in different lands, the people he met, and the new ninjutsu he discovered.
He might be more confident from the start. Since Jiraiya is known for his charisma and self - assurance, Naruto could inherit some of that. He may not be the underdog we saw in the original series as much.
One possible reason could be that Naruto might feel Jiraiya is being too overbearing in his training methods. In some fanfictions, Jiraiya might push Naruto too hard without considering his emotional state, leading to Naruto snapping.
One great 'Naruto Jiraiya fanfiction' is 'Jiraiya's Legacy'. It delves deep into how Jiraiya's teachings and influence continue to shape Naruto even after his death. Another one is 'Jiraiya's Unfinished Business' which focuses on Jiraiya's unfulfilled dreams and how Naruto might carry them forward. There's also 'Jiraiya: The Mentor's Path' that shows different aspects of Jiraiya's mentoring of Naruto from a unique perspective.
One possible plot could be that Naruto has a major disagreement with Jiraiya over his training methods. Maybe Naruto feels that Jiraiya is being too hard on him or not focusing on the right aspects of his growth. So, in a fit of anger or determination, he decides to ditch Jiraiya and go off on his own to train in a new way.
Yes, there are many 'Naruto Jiraiya' fanfics that focus on positive aspects like his mentoring of Naruto, his adventures, and his contributions to the Hidden Leaf Village. These fanfics usually avoid inappropriate themes and are more in line with the positive spirit of the Naruto series.