Disclaimer: I wish that I owned Naruto but I do not. The first paragraph is the prologue from the Kakashi Gaiden chapters so I don't own that either.
Around ten years ago… the Great 5 Shinobi Countries' Governments were in turmoil, and skirmishes involving the villages took place around the borders of each country. The prolonged wars took away the power of the Fire country… as the country was severely lacking in military power. A great many of those killed in battle were taken to Konoha Village. Afterwards, this was called "The Third Secret World War".
The Infamous Yondaime Hokage led his former Genin team towards their destination. Yondaime himself was to go to the front lines after he separated from his team consisting of two Chunin and a single newbie Jonin. Rin and Obito the two Chunin were to work under his lone Jonin, Kakashi. Their mission was to take out a bridge so their enemy wouldn't receive the supplies they desperately required.
The four ninja silently made their way through the knee-high grass and weeds hoping to avoid any Iwa ninja. They traveled in a standard single file line. Kakashi was in front followed by Obito, Rin and lastly the Yondaime himself. Everyone ready and alert halted at Kakashi's subtle hand gesture. Minato smiled approvingly at his student.
A lone obviously drunk or mental Iwa ninja with his hair tied in a pony tail at the front of his head was pressed up against a massive tree trunk, occasionally peeking at the motionless group. 'Shit, have I been spotted?' He looked around at the Konoha ninja again. 'Damn, they're good… I knew I shouldn't have agreed to participate in that sake drinking contest before I came.'
The Iwa ninja had strict rules and regulations beaten into his head ever since he could talk. One that should have stood out the most was 'If you encounter Konoha's "Yellow Flash" FLEE on sight.' Apparently his thought process had slowed down considerably and quite a few of his brain cells had committed suicide.
The retarded fool had been wiped out almost instantly. Well, only after Kakashi tried to give him the jolt of his life with a Chidori. All of his shadow clones had been zapped to death and he was about to stab the little silver haired bastard, and he would have gotten away with it too if it hadn't been for that meddling Yondaime and his pesky students. He had been too inebriated and couldn't decide witch fuzzy yellow ball he should impale first before some of his brain cells registered that one of the fuzzy yellow balls was behind him and holding a trippy looking kunai to his throat.
Minato was now leading his merry band of students after he scolded Kakashi multiple times and finally forbidding the younger never to use the Chidori ever again. Ironically he felt like a very mean but proud father, who consequently can't walk, think and watch where he's going at the same time. His forehead connected soundly with a low hanging branch. He heard three different reactions erupt from behind him. The first was a snort of disappointment, the second a concerned shriek of a mother hen not even half his age, and the third a flat out outburst laughing fit of amusement.
Holding his bleeding head Minato plopped himself onto a giant boulder that they had decided to camp by for the night. Obito had just left him to sit by himself after having a discussion about Kakashi's past, behind his back of course. He decided to check his pack to make sure he had everything that he would need on the front lines.
Multiple specialized kunai: check, medical kit: check, extra bandages: check, Icha Icha Paradise: definitely check. A perverted grin surfaced on his face as he cracked the orange covered book open to the page he had stopped reading at. He eventually fell asleep with the book covering his goofy grin and muffling any perverted phrases that he muttered in his unconscious state.
The next day the older ninja split away from the others. He arrived on the battlefield close to one of his comrades. An explosion nearby shot rocks every which way. Minato covered his head in a crouched position as he approached another Konoha male sporting a beard. "You're finally here, what took you so long?"
The Yellow Flash ignored the query of the other male. "What's the sitch?" he questioned. He ducked down even further as another wave of debris streaked by his location. "Gee, don't they know how to aim?"
"Um, Sir; we should be happy that they can't hit the broad side of a barn even if they were a foot away from it…"
"Yeah, I think I like your reasoning a little more than my own." Minato pulled his pack off and proceeded to haul a shit load of specialized kunai out. "Now, I want all of you to randomly throw these at the enemy if you would be so kind." The Yondaime flashed them a Good Guy Pose™ before performing a series of hand signs.
The few remaining Konoha ninja had completed their impromptu target practice session. In a flash, Minato who had been standing not far from them was now gone. Well he was mostly gone. Where he once stood were all of his clothes lying in a ruffled heap on the war torn ground.
The enemies were too busy cracking jokes and wolf whistling to even try to defend themselves against the almost completely nude Yondaime Hokage. His Konoha forehead protector emblazoned with the village's symbol was tied tightly to his forehead. Minato finally realized his predicament. He froze where he stood sheepishly covering what he could with his hands. His face had turned an interesting shade of red and only got darker when every ninja on the battlefield held up a video or camera phone and started recording footage and snapping pictures that would certainly make Konoha the laughing stalk of the entire ninja world.
After the battle, Minato had met back up with his students opting to remain silent except when spoken to. Rin and Kakashi had told him about Obito getting splattered under a massive boulder. Kakashi now sported a Sharingan in his left eye and a vertical scar that chicks would most definitely fawn over. They had destroyed the bridge and arrived back in the village in record time.
Minato had dismissed Kakashi and Rin while he went to his office in the Hokage tower. The only thing on his mind was to beg his sensei, Jiraiya to take him out for a good round of sake at the closest bar or tavern they could find and peek in the hot springs for old times sake. He hastily flung open the doors to his office on the top floor. His jaw hit the floor at the sight that greeted him.
A theatre sized poster of him wearing nothing but a smile mockingly stared back at him. On instinct his face went tomato red while he tried vainly to keep his mouth shut. A large hand clapped him on the back almost knocking him over. "Well, I'd say that's a new tacit for defeating our enemies…" the white haired Jiraiya stood behind him his tone laced with obvious amusement. "… Watch them die from blood loss from major nosebleeds." The toad hermit snorted in laughter. "I'm so proud of you; you're definitely one of my students." Jiraiya wiped a fake tear from the corner of his eye. "Oh, you should probably prepare yourself for a stampede of fangirls and fanboys, they're rabid I tell you." The Sannin snickered as he waved a goodbye to his former student.
Just after he opened the door it was torn off its hinges by a mad pack of ninja and civilian alike. Unfortunately all were drooling like idiots and waving posters of Minato's nude state, evidently wanting him to autograph them. He opened his mouth and let loose a scream that could put a siren or ambulance to shame by the sheer shrillness of it.
Minato Namikaze, Yondaime Hokage of Konoha shot up from his sleeping half laying half sitting position on the rock he fell asleep on. Icha Icha Paradise was clutched in his whitened knuckles. 'It was only a dream.' He kept repeating that to himself before finally falling back to sleep.
The next day he had just instructed the handful of remaining Konoha ninja to throw his custom kunai randomly among their Iwa opponents. He completed the hand signs for his Shunshin no Jutsu better known as the Body Flicker. Before any of his targets could comprehend what had happened they were dropping like flies. Before Minato realized anything his eye had caught sight of a camera phone.
It is said that Konoha only survived Iwa's attacks because none of the Iwa ninja could find it in their heart to attack a full grown man blatting like a baby. Minato was revered as a hero although he was never the same again. His days after the traumatizing event were spent curled into a ball under the desk in the Hokage's office. He resigned from being Hokage, forcing old man Sarutobi to come out of retirement and retake the title of Sandaime Hokage. Minato stays under there to this day giving the Hokage foot massages and singing to himself like a stoned mental patient. The Kyubi wasn't sealed in Naruto by him but by his stunt double. Now you know the true story of Minato Namikaze, great hero of Konoha and the Sandaime Hokage's personal foot massager.
A/N: I don't think it is as good as it could have been, but it still make you laugh so its served its purpose.