Iruka-sensei is the teacher of Naruto, Sasuke, and Sakura when they were still going to school. He is the first person to acknowledge Naruto. Iruka also grew up with no parents and knows how Naruto feels. He used to act stupid to get attention because he didn't have parents to praise him. He sometimes buys Naruto ramen at a restaurant. His rank is Chuunin. And since I don't know what his full name is, I just put him down as Iruka-sensei.
Hokage-sama is like the mayor of the Leaf Village, I guess. He is the strongest ninja in the village, which is how you get to be the Hokage. I don't know his real name, so I just put him down as the villagers call him. He has a grandson (I don't know what happened to his son/daughter tho) named Konohamaru who desperately wants to take over as Hokage. The Hokage often uses this crystal ball thing to look in on what Naruto is doing.
Mizuki-sensei is a teacher, like Iruka. He's evil tho. He pretended to give some friendly advice to Naruto about graduating, but he really wanted to get ahold of this forbidden scroll by telling Naruto that if he stole the scroll and learned one of the jutsu's in it, he would graduate. He was planning on killing Naruto in a forest place, but Iruka came and interfered. Mizuki told Naruto that he was the Nine-Tails Fox Demon and Naruto ran away. Mizuki tried to kill Iruka, but then Naruto came to the rescue, using his newly learned skill, the Shadow Clone Skill (I think). Mizuki got beat up by Naruto's multiple Shadow Clone's and Naruto finally got to graduate.
Konohamaru is the grandson of the current Hokage of the Leaf Village. He hates the fact that everyone can only think of him as the grandson of the Hokage, so he often pops up to do a surprise attack on his grandfather. After meeting Naruto, he wanted to learn the Sexy no Jutsu from him to defeat his grandfather and become Hokage. He has a tutor named Ebisu. Konohamaru tries to follow Naruto around (rather unsuccessfully) disguised as common things (i.e. part of a fence, a square rock). I guess Konohamaru kinda looks up to Naruto, but he also declared him as his rival for the Hokage title.
Ebisu is the elite tutor of Konohamaru. He considers himself to be a shortcut to becoming Hokage, because he has taught several other Hokage candidates. He really seems to despise Naruto, who he always thinks of as the Nine-Tails Demon. Konohamaru tried to use the newly learned Sexy no Jutsu against him, but to no avail. Then Naruto jumped in, using the Harem no Jutsu, where he combined Sexy no Jutsu and the Shadow Clone Skill, and 'defeated' him.