Iruka always wanted a quick, violent death.
It seemed a very odd request, and when he told his teacher he wanted to die fast the man looked panicked and pulled Iruka out of the class to give him a long talk about the joys of life. Iruka laughed, because he wasn't going to kill himself, but he wanted to die quickly and messily, rather than waste away in a hospital bed.
For a long time it seemed very likely. Gennin and Chuunin died violently every month in missions gone awry, or missions that went perfectly well. Iruka threw himself into fights with a reckless abandon no one expected of him, and he scared one of his teammates so badly she wouldn't stay anywhere alone with him. It didn't really matter, because neither of his teammates understood wanting a quick, violent death. They wanted to grow up and have kids. They wanted a life.
It seemed Iruka was very likely to get his wish when he reached Chuunin. He had attained several life threatening injuries as a Gennin, and the likelihood of him avoiding even worse injury on a harder mission with his reckless way of fighting wasn't very likely at all. Iruka's old teammates looked at him like he was a dead man, but his Jounin instructor only shook his head and let Iruka be.
However, something happened to change Iruka's chances. The Academy was deathly short on teachers, and they needed a Chuunin with a good knowledge of the basics. Unfortunately Iruka had an excellent understanding of the basics of almost everything, and somehow, by some fluke, someone picked him to be the newest teacher at the Academy.
The first day Iruka walked into the room filled with children, and realized he probably wouldn't die the way he wanted to after all. The children looked at him with expressions ranging from curiosity and mischief to fear and uncertainty. Iruka wasn't likely to find a violent death anytime soon. Perhaps a tragic and pitiful one, but not very violent.
It was a bit depressing to face the fact he might just end up wasting away in a hospital bed, or have some trivial stupid accident end his life. Iruka was depressed through the first month of classes, in which he learned he had five separate trouble makers in his class, and they seemed to be competing with each other to see who could pull the most pranks.
It wasn't until Iruka had graduated his first class he realized what he was teaching. Three of his students-the most accomplished of the class- ended up dead in a week. They were torn apart by the enemy, and one was brought back in a bucket. Iruka was sickened by the sight. He'd known the children through the past few years of their life, and seeing them dead in the manner he had proudly said he wanted to die was shocking.
Iruka's teaching style changed dramatically over the next week. He wasn't directly responsible for the children's deaths, but he would always feel he was. Iruka drilled his students on everything mercilessly. He took them for impromptu field trips to the hero's tone, or just out walking while he taught them. He made them tell why they wanted to be Shinobi, and what they liked best of everything. He taught them to live and live well, because their death could be minutes away.
"Oi, Iruka-sensei, are you gonna answer my question?" Naruto asks with a slight frown. "Oi, Iruka-sensei!"
"Oh, sorry Naruto, I was just thinking," Iruka smiles, and looks at Naruto. "You wanted to know how I wanted to die, eh?"
Naruto nods impatiently. "Yeah, that's right. Hurry up an tell me, Iruka -sensei."
Iruka smiles a little less. "I want to die in the classroom still grading papers." Naruto laughs mightily to that, and Iruka just laughs along. It is probably the truth anyway. Iruka isn't sure he wants to die violently anymore, and he likes to teach now. He feels he needs to teach, and to keep on teaching. Still, Iruka knows if a quick, violent death comes his way he won't run from it.
A/N:You may wonder 'Why did Naruto ask that question?' He was curious. So he asked, and Iruka told him. Kids.