facts about oroch, jiraiya, tsunade mythology in Japan..

Orochimaru (大蛇丸), featured in the Japanese folktale Jiraiya Goketsu Monogatari, is the arch-enemy of the ninja Jiraiya. He was once named Yashagorō (夜叉五郎) and was one of Jiraiya's followers, but he was overtaken by serpent magic. Having changed his name to "Orochimaru", he gained the ability to turn himself into a giant serpent. He attacked Jiraiya and his wife Tsunade and defeated them with his venom (only for another follower to save the couple's lives afterwards). "Orochi" is the name of a giant eight-headed snake in Japanese mythology. The kanji (大蛇, usually pronounced daija) literally mean "giant snake" or "serpent".

"Jiraiya" means "coming by oneself" which is a description of his personality; quietly appearing and disappearing from Konoha at any time. The kanji on his forehead protector (油, Abura) means "oil", which can point to his oil spitting for ninjutsu.

Jiraiya is named after the character of the same name from Jiraiya Goketsu Monogatari (児雷也豪傑物語, "The Tale of the Gallant Jiraiya"). The Jiraiya in this story excelled in summoning a giant toad (the toad itself was sometimes called "Jiraiya") and toad magic. In that story, Jiraiya and Tsunade were a married couple. There, his name is written as "児雷也" meaning "Young Thunder" which in turn comes from the name Garaiya (我来也, "I came") from the Chinese story Kaishi (諧史).[1]

Legend of the Gallant Jiraiya
" Jiraiya (literally 'Young Thunder'), was the scion of a powerful clan from Kyushu. When the family fell on hard times he went to Echigo province, now Niigata Prefecture, became a freebooter and rose to the position of chief of a chivalrous band of robbers.

He was initiated into toad magic by an immortal who resided on Mount Myoko, popularly known as Echigo Fuji. He failed to overcome and kill a hated rival, an older man named Sarashina, who was the cause of his family's ruin.

Jiraiya fell in love and married Tsunade, a beautiful young woman who was skilled in snail magic. Later, one of Jiraiya's followers, Yashagoro, was overcome by the spell of a serpent and became skilled in serpent magic. He took the name Orochimaru (Orochi means `monstrous snake') and attacked Jiraiya. Together with his wife, Jiraiya battled with this magician, but they were infected with the serpent's venom and fell unconscious. Fortunately another of Jiraiya's followers, whose life he had once saved, came to his rescue. At this point, without conclusion, the tale abruptly ends.

Toad, serpent, bird, spider, and snail magic were the principal types of magic practiced by thaumaturges in old Japan. They were supposed to be incompatible with each other, but in this story, at least, love found a way. "