Jiraiya was a student of the 3rd hokage and also was the sensei of the future 4th hokage. Jiraiya is one of the Three Legendary Sennin's, with Tsunade and Orochimaru. He is the "
Rock" as the three are heavily based off the "
Rock,
Paper, Scissors" game, or also known as Janken.
You first
see him peeping in the women bathing place to "collect material".
Naruto then gave him his nickname "Ero-sennin". Although he is kinda stupid and funny, he truly is a master ninja. He teaches
Naruto to control his 2 chakras and to summon frogs.
As such, Jiraiya's fighting techniques are mostly defensive, His "Underworld Swamp" immobilizes a large amount of ninja's in a marsh, and his "Underworld Spines" defend him from any physical attack. He mostly relies on his summoning frogs to aid him, though he rarely summons Gama Bunta.
There might be a
good reason why he specializes in defensive techniques, and that is because he a complete and utter
pervert, who writes a series of books known as Icha Icha Paradise, a book Kakashi himself adores. As such, he has grown so adept at peeping he is rarely caught.
Also see Ero-Sennin
