Jiraiya was, in modern times, one of Konohagakure's most powerful and renowned shinobi. He was one of the three legendary Sannin, alongside Orochimaru and Tsunade, who with him were the students of Hiruzen Sarutobi, the Third Hokage.
Background
Jiraiya was born decades before the start of the series and as a child, became the student of Hiruzen Sarutobi, the Third Hokage, alongside Orochimaru and Tsunade. His place on the team was identical to that of Naruto Uzumaki's on Team Seven in that Jiraiya was the most goofy and fell for the same ovious traps time after time. He had a crush on Tsunade, which in later years developed into a one-sided love. After some lecturing from his teacher, Jiraiya eventually became more serious as a shinobi, and was able to discover his natural affinity with toads(in the anime, it shown that he was still a student of Hiruzen and performed the Summoning Technique without a contract, thereby being reverse summoned himself to Mount Myoboku, where the shinobi toads reside). While there, the Great Toad Sage relayed a prophecy to Jiraiya that he would one have to decide whether a student he was to train would destroy the world or save it. During his stay there, he trained in senjutsu with Fukusaku and Shima, two of the elder toads.
In later years, during the Second Shinobi World War, Jiraiya and his teammates, Orochimaru and Tsunade, teamed up to fight against Amegakure leader Hanzo together, being the only ones out of their platoon to survive his wrath. Though they themselves were eventually defeated and left at his mercy, Hanzo was impressed with them and bestowed upon them the title of "Konoha's Legendary Three Sannin" in return for their names and letting them live to fight him again in the future. After the battle, as they rested in a cave, the Sannin encountered three Amegakure orphans, who Orochimaru questioned if they should kill to keep them from suffering. Jiraiya, however, took pity of the children and decided to stay with them until they could at least take care of themselves. One day, after hurrying to the scene of an attack by a Chunnin shinobi who had tried to harm Yahiko, one of the kids, Jiraiya was stunned at the sight of the Rinnegan in the eyes of Nagato, another of the kids, who had killed the shinobi. Believing that Nagato was the child told of in the prophecy by the Great Toad Sage, Jiraiya decided to train Yahiko, Nagato, and Konan, the final of the three, as shinobi so that they could fight for themselves. After three years Jiraiya, impressed when they managed to easily dispatch a shadow clone of him, decided to part from the trio so that they could pursue their own goals. He received word of their exploits, but believed they died in an undisclosed incident. Jiraiya, at one point, even wrote a book inspired by Nagato before leaving, which wasn't popular.
Eventually, Jiraiya came to train another team of his own, the most famous of which was Minato Namikaze, who eventually became the Fourth Hokage of Konohagakure after Jiraiya left the vilalge in pursuit of Orochimaru. Minato read Jiraiya first book(the one he wrote about Nagato) and liked it. The main character, Naruto, reminded him of Jiraiya and he wanted to name he and his wife, Kushina's unborn son after him. Jiraiya warned that this would make him the boy's godfather, but Minato and Kushina didn't mind.
Jiraiya, after Orochimaru betrayed and fled Konohagakure, attempted to follow him and convince him to return, but was attacked. He eventually came to terms with the fact that Orochimaru would never change or return, and left Konohagakure to track his movements, despite Hiruzen's wish that Jiraiya take over as Hokage, as he felt that following Orochimaru was more important. He eventually discovered that he had joined a criminal organization called Akatsuki, whose purpose he uncovered after examination of their members. He also, along the way and throughout the years, authored the popular Icha Icha series, based on his own love experiences retold in a comical way. The series paid off, as Jiraiya became very wealthy from the sales.
Naruto
Jiraiya made his debut in part 1 of the series knocking out Ebisu, a jonin of Konohagakure, out when he attempted to stop Jiraiya from peeking in the women's bath house. After his student, Naruto Uzumaki, then demanded that he teach him the technique Ebisu had tried, Jiraiya ditched, but was continuously found by Naruto. Eventually moved by Naruto's Sexy Technique, which he was amazed at due to his perverted nature, Jiraiya took Naruto under his wing, and undid the Five Elements Seal Orochimaru, Jiraiya's former teammate, placed on the boy to unstable his chakra. Jiraiya went on to teach Naruto the Summoning Technique and give him their blood contract. Though Naruto failed for weeks to summon a toad, Jiraiya eventually put the boy in a live or die situation and he managed to master the technique with aide from Kurama, his tailed beast, who Jiraiya was aware of. Shocked that Naruto summoned his old friend Gamabunta, Jiraiya watched as he tried to earn Gamabunta's respect, later showing him the contract Naruto signed. Jiraiya later appeared when Orochimaru attempted to carry out his plan of destroying Konohagakure, and used his Food Cart Destroyer Technique to combat Orochimaru's giant snake summons. After the attack was thwarted, Jiraiya was later somewhat saddened when he saw Hiruzen Sarutobi, the Third Hokage, had died.
Later, when the village elders Koharu and Homura came to Jiraiya and informed him that he had been chosen to be the Fifth Hokage, Jiraiya offered to find his old teammate, Tsunade, who he felt was better suited for the title than himself. He went to Naruto and persuaded him to come along with the promise of teaching him a new technique. On the road, Akatsuki members Itachi Uchiha and Kisame Hoshigaki, spotted them and Itachi, desiring to capture Naruto without battling Jiraiya, placed a genjutsu on a pretty woman to distract him. He seemed to have fallen for the ruse, but saw through it and returned in time to prevent the Akatsuki duo from getting Naruto. As Sasuke had arrived before him, Jiraiya allowed him to fight Itachi, but was proven mistaken and used his Summoning: Toad Mouth Bind technique to entrap Itachi and Kisame when Naruto attempted to interfere. Though nobody had ever survived this technique, Itachi burned through the walls with Amaterasu and they escaped, failing to capture Naruto. Jiraiya and Naruto continued their journey, him teaching Naruto his Rasengan technique to keep him occupied. Although it took weeks to find her, Tsunade initially refused the title of Fifth Hokage, and ended up making a bet with Naruto about mastering the Rasengan. During the following days, Jiraiya went drinking with Tsunade a couple of times, knowing she had had contact with Orochimaru, and told her the second time that if she helped him and betrayed Konoha, Jiraiya would personally kill her. She then spiked his drink and left him massively weakened to keep him out her way. The next day, after getting the details from her assistant, Shizune, he, her, and Naruto left in her pursuit. Later glad to see she refused to help him, Jiraiya and the group found her battling Orochimaru and his right hand, Kabuto Yakushi, who overcame Tsunade.
Jiraiya decided to take on Orochimaru and have Shizune fight Kabuto, while Naruto looked after Tsunade. However, as they were both weakened, neither could do the other much harm, but were evenly matched. After Kabuto defeated Shizune, but Naruto defeated Kabuto with a mastered Rasengan, Jiraiya became impressed. After Orochimaru attempted to attack the badly hurt Naruto, who Kabuto struck in the heart, Jiraiya tried to stop him, but was countered and repelled by Orochimaru, who ended up stabbing Tsunade through the chest instead. Tsunade lived though and withstood further attacks, before repelling Orochimaru, and all three of the Sannin then summoned their personal summons. In a deadlock fight, Jiraiya and Gamabunta managed to pressure Orochimaru's Manda, before he became disabled by Tsunade, who defeated Orochimaru. Afterwards, the group rested and returned to konohagakure, where Tsunade became the Fifth Hokage. Later, after Sasuke Uchiha's defection from Konohagakure and the unsuccessful attempt to bring him back, Jiraiya offered to take Naruto with him on a training trip, as it would be three whole years before Orochimaru would have the chance to take Sasuke's body as he wanted, and the two left for two and a half years of training away from Konohagakure.
In part 2, Jiraiya and Naruto returned after their training to Konohagakure, where Naruto went back to be a part of Team kakashi, while Jiraiya left to go and gather intel of the Akatsuki, but later returned to inform kakashi and Yamato of Naruto's four-tailed form under Kurama's chakra, before leaving again. After a long absence, Jiraiya returned with information on the whereabouts of Akatsuki's leader, informing Tsunade that he, known as Pain, was centered in Amegakure, while also discussing how to capture Itachi Uchiha. Though Tsunade was wary of Pain's power, Jiraiya told her to bet that he would die, so as to ensure he would live given Tsunade's bad luck at gambling. He then left and infiltrated Amegakure, where he took two local shinobi hostage to find out some information. Shocked when he learned that Hanzo, the former leader of Amegakure, had been defeated by Pain without aide, Jiraiya decided to leave the seal key to Kurama's cage to Naruto, before leaving to try and learn more.
He eventually encountered his old student, Konan, who he managed to easily subdue and take hostage, before Pain arrived. Recognizing Pain as his old student Nagato due to his Rinnegan, Jiraiya became shocked at what he had become. As Pain freed Konan, Jiraiya engaged him in battle, the two both using the Summoning Technique. Jiraiya summoned his old friend Gamaken to combat Pain's various summons, all of which Jiraiya took out. After he could, Jiraiya summoned his two partners, Fukusaku and Shima, to help him reach Sage Mode so that he could fight at full strength. Pain, however, summoned two addtional bodies, also with the Rinnegan, to counter. Even in Sage Mode, this trio proved invincible, with one absorbing Jiraiya's techniques and them all being able to share a line of view to dodge any attack. Jiraiya and his team fell back, and decided to use genjutsu to disable the bodies. While this was successful and Jiraiya took them all out, another appeared and severed Jiraiya's arm, and he soon found himself confronted by the Six Paths of Pain, with the three bodies he had killed revived.
Heavily outmatched, but still trying to succeed, Jiraiya managed to recapture the first body of Pain he saw and kill it, only to recognize who he really was afterwards. Shima returned home, and Jiraiya and Fukusaku both went to confirm his theory about the other bodies of Pain. Realizing that all the bodies were shinobi he knew before, Jiraiya figured out who Pain was, but his throat was crushed by one of the bodies before he could tell and he was pinned to the ground by the other four. Fatally wounded, Jiraiya managed to enscrib a message onto Fukusaku's back about Pain, before the rock he was lying on was destroyed, sending him into the water. Reflecting on his fate, Jiraiya, considering it glorious, died with a smile on his face as he sank to the bottom of the watery depths.
Personality
Jiraiya was a super-pervert by his own admission and developed a technique to help him to spy on naked women as a child. He was also very loyal to Konohagakure, to the point of threatening to kill his teammate,Tsunade, if she ever betrayed the village, despite his love for her. He also had a strong relationship Naruto Uzumaki, his godson, who he trained into an excellent shinobi. Jiraiya dearly loved his past students, and was brought to tears at Nagato's corruption. He also was a strong believer in peace, and sought to find a way to make the world a better place, leaving this task to Naruto when died. Jiraiya also tended to be a show-off, and strike poses often.
Abilities
As one of the three legendary Sannin and a Sage, Jiraiya was an extremely powerful and skilled shinobi, easily Kage-level in his own right, and was the first choice for the position of Fifth Hokage, which he turned down. His power was so great that even powerful members of Akatsuki, like his student Konan, were easily defeated and subdued, while others like Itachi Uchiha and Kisame Hoshigaki, a Mangekyo Sharingan master and former member of the Seven Ninja Swordsmen of the Mist respectively, chose not to face him in battle, fearing that even their combined efforts against Jiraiya would only be good enough to constitute a stalemate. Itachi stated that even if they had allies, the result would have been unchanged. Kisame himself openly admitted he was no match for Jiraiya, saying he was on a whole other level. Even his former pupil Nagato, a Rinnegan user with extraordinary power, was almost defeated by Jiraiya, despite outnumbering him from the get-go, causing the much less experienced opponent to marvel at Jiraiya's power, saying he would not have defeated him had he had prior knowledge of Pain's secret.
Jiraiya had a natural affinity with toads, which showed as he able to summon toads of various sizes with great ease, even summoning parts of them to use for battle or defense purposes. This natural skill caused Jiraiya to become known as the Toad Sage. With just one technique, his Toad Mouth Bind, he trapped and drove away both Itachi and Kisame in their encounter in part 1. Jiraiya also had great skill with barrier and sealing techniques, which was shown in his ability to seal Amaterasu's flames and Naruto's four-tailed Kurama form. He also could create barriers capable of sensing attacks from anywhere and entrap opponents with great ease and speed. Jiraiya was very skilled at taijutsu, having great strength, stamina, and refelxes. He was also quite perceptive, able to quickly reason what was causing Naruto to not have any good control over his chakra. Jiraiya's greatest fighting ability was Sage Mode, which massively enhanced strength, speed, and the power of his techniques. To enter Sage Mode, Jiraiya would summon his partners, Shima and Fukusaku, to latch to his shoulders and continuously gather Sage energy for him to allow him to remain in the mode for as long as he pleased. Also, though Jiraiya had basic knowledge of how to recognize and counter genjutsu, he couldn't use it, and relied on Shima and Fukusaku to do so for him.