Umino Iruka

Umino Iruka (うみのイルカ, aka Iruka umino in the english version) is a chunin -level shinobi of Konohagakure who serves primarily as an instructor at the Ninja Academy.

Background
Iruka's parents were killed in the Nine-Tails' Attack on Konoha twelve years before the beginning of the series. Initially, a young Iruka was present on the battlefield, and wanted to stay in order to protect his mother. His father declared that it was the parents' duty to keep their child safe from harm. He was forcibly removed from the battlefield by an unknown shinobi.[3 ]

With his family gone, Iruka had no one to give him attention. Iruka thereafter became a prankster much like Naruto would later become, trying to gain attention to stave off his loneliness.[4 ] He would spend his time at the monument where his parents' names were engraved, and, in his darkest moments would be cheered up by the Third Hokage.[5 ] Mizuki was a childhood friend of Iruka's after the Nine-Tails Attack, and usually made him feel better. In the anime, it was noted that due to other people giving Iruka more attention than they do to Mizuki, Mizuki's kindness to Iruka revealed to be an act just to gain the Hokage's approval, all the while making Iruka miserable discreetly.