Put Yourself in My Shoes
Tsunade had finally crossed the wrong people, and simply running away was no longer an option. These weren't the usual petty crime bosses or even full-fledged Yakuza she'd long been accustomed to; somehow, they had captured Shizune.
And they were playing hardball.
"What do you want?" spat Tsunade. "I'll kill you all if you harm her!"
"And you'll never find her if you do," said Deus X. Machina, the Mysterious Stranger. "But I'm sure we can come to a more… amicable arrangement."
Tsunade didn't think the arrangement was all that 'amicable', to tell the truth. But she'd been asked to do stranger things in her life than use her unique genjutsu to transform into a short, whisker-cheeked boy and spend a day in Konoha.
xxxxxxx
Regarding the Sannin, people generally think of Jiraiya as the super perv with the flashy ninjutsu; Orochimaru as the evil genius with the freaky kinjutsu; and Tsunade as the alky medic with the… big tits.
That assessment was not, of course, entirely inaccurate; but then, neither was it completely correct. For even though Tsunade didn't have the showiest jutsu, she did have chakra-enhanced super strength and a ginormous, acid-spewing slug summon - meaning she was still not someone you wanted to piss off.
Repeatedly.
xxxxxxx
As the dust settled, the two remaining combatants appeared to be struggling to keep their feet.
"Minato's son," hissed Tsunade. "My godson!"
"It was a secret that had to be kept, Tsunade," the aged Hokage choked out. "The boy would have had powerful enemies…"
"And he should have had even more powerful defenders!" shouted Tsunade, arcing double chakra-scalpels through the old man's chest.
And so Sarutobi Hiruzen, the Sandaime Hokage of Konohagakure no Sato fell, heart shattered (or diced, to be more technically accurate), as the Great Tree of Konoha burned.
xxxxxxx
Tsunade gathered up the boy where she had left him earlier in the day, safely hidden and sleeping under a simple iryōjutsu technique.
It had been an awkward initial confrontation, followed by fearful, half-whispered accusations of the trouble she must be making for him while in his guise; and then he told her his story. And she couldn't help but be moved by the boy's words, naïve and hopeful in the face of such monumental adversity. ("Ashley Kinder Syndrome? Or even Stockholm Syndrome," the medic-nin in her diagnosed.) For a moment, when he spoke of his dream of becoming Hokage, she could almost see her little brother, Nawaki in his place - but this would be her brother betrayed by those closest to him, as opposed to giving his life in pursuit of his dream (a realization that finally brought her some closure, and also galvanized her will to do what needed to be done).
xxxxxxx
Tsunade found Shizune by the broken village gate, and roused her from the illusionary technique that Machina had left her in. ("You were playing slots, and losing," Shizune meekly explained. "It simply never occurred to me that I was in a genjutsu.")
xxxxxxx
As the three walked through the forest, Shizune tried and failed to make sense of recent events. Finally giving up, she asked, "So, where are we going now, Tsunade-sama?"
The answer, not so surprising as it might once have been, was (as always) quietly accepted.
"We're going to find my worthless ex-husband," Tsunade said. "And we're going to kill him."
A.N.
I really hate the 3rd. That phony 'grandfather' act makes me want to puke. He is a cold, manipulative bastard with an agenda, just like canon Danzo - they are two sides to the same coin. He glibly tells the world that Naruto is a walking atom bomb/jinchuuriki, but then says that he can't reveal Naruto's parentage because THAT might cause problems. (Seriously, which is worse?) He makes sure the kid is utterly defenseless, strips him of his family, heritage, inheritance, and any chance of a normal life. But hey, a couple times a year he spends a buck and buys the kid a bowl of ramen. What a guy. "Sorry everyone in the village treats you like crap, Naruto, but here's some cheap-ass soup to make up for it." And then he's got the freaking balls on him to tell the kid that "the Hokage has to care for everyone in the village, like family." What an evil prick. Now you know why he's the only kage to become old enough to retire, when the average life expectancy for a ninja is probably around 30.