A student and their teacher are like parent and child. They can become really close to each other and a trust forms. They have faith in each other. They help each other through hard times. A teacher passes on their knowledge to their student just as a parent does to their child. A perfect example of this bond would be Jiraya and Naruto. Jiraya has been there for Naruto and has taught him so much. He taught him how to summon Gamabunta http://naruto.wikia.com/wiki/Gamabunta, how to use the Rasengan http://naruto.wikia.com/wiki/Rasengan, took him on the journey to find Tsunade, was there during the battle of the legendary Sannin to protect Naruto from Orochimaru, and even at his death, he assisted Naruto and the rest of Konoha by sending a very important message.
I look at them as the perfect teacher-student role models. There are many others like Gai and Lee, Kakashi and team 7, but these two stand out the most for me.
