While the Boruto series has been full of unexpected twists lately, in the original Naruto series, one of the most shocking moments was the revelation that Itachi was not at all evil, but a hero caught in a tragic situation. His main reason for joining the Akatsuki, an organization that wreaked havoc in the shinobi world, was to protect Konoha.
While it is known that Itachi chose this path of his own accord, out of his love for his brother and Konoha, a fan theory suggests that Jiraya, one of the legendary Sannin, may have been in contact with him all along.
Naruto is a pretty long series with numerous characters and intricate worldbuilding. However, there are several aspects of the story that mangaka Kishimoto forgot to resolve, and this might be one of them. Whether intentional or unintentional, it does allow for some room for subtelty, which should be appreciated because not everything needs to be stated explicitly.
Naruto fan theorist provides evidence backing the claim that Itachi was spying for Jiraya
It has been confirmed in Naruto by Hiruzen that Itachi was spying on the Akatsuki, although only the Elders were supposed to know this. However, what remains unclear is whether Jiraya was obtaining his information about the Akatsuki members and their inner workings from Itachi.
This theory has been floating around for years now and seems quite plausible, although it is not officially confirmed in the series. One Naruto fan theorist and YouTuber, New Horizons (@New_Horizons), has now made the theory indisputable by offering substantial evidence. The most credible starting point is Jiraya's admission to having informants, who supplied him with information regarding Orochimaru's activities and other Akatsuki members.
Yet, back when the Akatsuki was mostly involved in espionage, Jiraya knew only of Itachi's affiliation to the group. There were several other members in Akatsuki, about whom Jiraya should have known, especially Itachi's partner in crime, Kisame, had he been getting his information from elsewhere. According to the YouTuber, Itachi may have only informed Jiraya that he was in the Akatsuki at that point.
New Horizons then introduces two significant pieces of evidence to reinforce the idea that Jiraya received information from Itachi. The first pertains to Itachi's death.
On the same day when Itachi orchestrated his own death at the hands of his brother, Sasuke, Jiraya coincidentally learned that Pain, the leader of the Akatsuki, was in the Rain Village.
It is possible that the information was sparse because Itachi had already shared everything he knew with Jiraya by that point. This explains why Jiraya and Danzo, who was aware of Itachi's role as a spy, both believed Tobi to be Madara Uchiha.
New Horizons' final argument emphasizes that the other Great Countries knew almost nothing about the Akatsuki, as evident during the Five Kage Summit, where speculation and paranoia ran high. In contrast, Jiraya possessed a wealth of information about the organization, hinting at a connection with Itachi.
Thus, fans believe that it cannot be a mere coincidence that Jiraya learned about the Akatsuki every time Itachi and the other members made a move. This very fact supports the theory that Itachi was somehow passing on information to Jiraya.
It is possible that Jiraya and Itachi never met and that the intel was delivered through intermediaries. Maybe Jiraya never knew that it was Itachi who was supplying him with information. However, the content of the intel suggests that Itachi was Jiraya's informant.