Naruto's Sensei [Teachers]

 
In Viz's English adaptation, they've translated "sensei"
as "master"... Why? Who knows.
Umino Iruka Iruka : Naruto's first Sensei at the Ninja Academy. Iruka's parents were killed fighting the Nine Tails, which Naruto has sealed inside of him. Even though Iruka knows this, he doesn't treat him like the other villagers do. Iruka is the first person to acknowledge Naruto's existence and is the closest thing to a father or older brother he has.
Hatake Kakashi Kakashi : Naruto's second Sensei as a Genin. He passes Naruto, Sasuke and Sakura's three-man team and trains them to become Chuunin. He too knows what Naruto really is, but doesn't hold it against him. He knows the boy's potential as a Ninja is great and seems like he's not really letting us in on everything he knows...
Jiraiya Jiraiya : Naruto's third Sensei. Naruto doesn't know this self proclaimed super-pervert is really one of the legendary San-nin until well into his tutelage. Jiraiya is more of a slacker than Kakashi, but while Kakashi is off training Sasuke to control the curse seal, Jiraiya takes the time to help Naruto control the Nine Tails' chakra. He also gives him a contract with which he can summonin nin-toads.


Some other teachers and students...  
Nidaime Hokage:
Homura [future councilman]
Sarutobi [future Sandaime]
Koharu [future councilwoman]

Shodaime Hokage is on the left.
Sandaime Hokage [Sarutobi]:
Orochimaru,
Jiraiya,
Tsunade
Jiraiya:
?,
?,
[the future] Yondaime Hokage
Orochimaru:
Mitarashi Anko
Yondaime Hokage:
Rin
Uchiha Obito
Hatake Kakashi
Hatake Kakashi:
Uchiha Sasuke,
Haruno Sakura,
Uzumaki Naruto