Chuunin, (part 1: 25 years)
He is the teacher that basically raised Naruto in his classroom, fed up by his daily pranks. When graduation comes, Naruto fails again for the third time. Iruka fails him, letting him think he doesn't care for the boy. But in the first battle against Mizuki-sensei, his true feelings for Naruto come out, showing the boy he knew how he feels, since he lost his parents during the Kyuubi attack and was alone all the time... Acting stupid to gain attention. They become close friends, some might even say Iruka should become his father one day.
Literally translated his name means 'Dolphin from the sea'
KakashiFangirl: No way, Iruka is so lame, he's only a Chuunin, Kakashi Hatake is way better!
IrukaFangirl: Oh Yeah?! Well he raised Naruto! If it weren't for him there wouldn't be a squad 7!
KakashiFangirl: Ah, touche...