He didn't mean to be late.
Had he been able to choose, he would've been an active person. Hatake Kakashi was indeed active but it was entirely forced. Had it not been for his sheer amount of willpower, he would've been snoozing far more than he did. He wasn't a morning person, yet all signs of weariness were hidden behind his mask. He always wore the mask. Ever since somebody had noted, when he started at the ninja-academy so many years ago, that he really did look like that kid from the C-class. That was when he got used to wearing the mask. He might've had a lot of other explanations to it but no matter how much he denied it, he knew this was the real reason.
He was always late for the training sessions, he knew, but somehow he couldn't be bothered to get out of bed in the morning. It was, as he liked to call it, the legacy of his mom, the only legacy. He had not known his mom, but by analyzing his dad and subtracting his features from his own, Kakashi would imagine how his mom had been. He knew he had a cousin, an entire family in fact. Nothing short of an entire clan, but not one second had he ever considered joining up with them. He didn't know why this was, they were just, not like him, and yet like him in scarily many ways. He knew their son, and in him he saw a likeness to himself. Several times he had prevented himself from saying this boy's trademark quote, tempting and very relevant as it was, he was a copyninja after all, and he had been in MANY situations where this word was perfectly fit.
To Kakashi, this legacy was an undeniable fact. He knew why he always was late. Perhaps he should take up his ancestry. Nobody deserved half a family. Yet he hesitated, maybe he wasn't just working hard enough. Joining his clan would just be to surrender. Instead he fought. He fought all what his instincts told him. He was still late for session. Sakura was going to be mad again he knew.
"troublesome!",
he said, for the first and last time ever. He knew he was Hatake Kakashi and nothing could change that.
Besides, Nara Kakashi sounded lame
A/N: okaay, this is a random idea I came across while reading a fanfiction (can't remember which, but it was something where Shikamaru was late for training). I kinda juggled a bit with the idea before deciding that, even though ultimatly random, it had a strange quality. This is just a oneshot i wrote cuz as far as I remember, you haven't been told about Kakashi's mom.