Summary: the elemental nations have been visited by the outside world and warnedof the approaching danger that goes by the name of the fire nation. And the person that brings the message. The Avatar himself.
It was another normal day in konohagakure no sato. The sky was blue, the birds were chirping and singing their merry tune's, a eight legged bison was flying towards the Hokage tower.
" Ah what a refreshing day." said our favorite blond "wait something is wrong." 'sky check, birds check, flying bison heading towards the hokage tow..' " Oh crap Tsunade Obaa-chan I'm coming",Naruto then replicated the yellow flash and was away from his window, out of his apartment, and down the street in under 10 seconds.
Meanwhile in the Hokages office Tsunade was filling out paper work which she was convinced that is the bane of her existence decided to take a sake break in front of her window. What she saw didn't please her a giant fuzzy creature slammed through her window. Of course being a sannin got out of the way but wondered what it was.
"Obaa-chan are you alright?"
"I told you to stop calling me that! But yes I'm alright. Search whatever that is for clue's to what it is."
When they rolled the giant bison over they found 4 teenagers. Tsunade ran a medical scan over them.
"They seem to have sustained multiple katon injury's recently."
" Thats it?" Naruto asked in utterly confused about these weird people
"Well the smaller boy's chakra system is unlike any other It reminds me of Pein's whenyou brought met the original body also his tattoo's are out of the ordinary. The small girls' body has such a earth affinity that its like healing a stone wall and the older girls body is the same with the replacement of earth for water."
"What about the boy?" asked Naruto
"nothing special but his sword is" and she was cut off by Kakashi.
" A chakra fang." a completely stunned Kakashi said "I thought that there was only one my father's"
"I wonder if these people know what they possess"said Naruto
"What do we possess, and were are we?" said the newly awakened boy.
"Your in Konohagakure no sato, you and your flying creature crashed through my office window." Tsunade said in the most caring voice she could.
"Flying thing? Oh you mean Appa. Sorry about your window" said the boy, "how much would it cost?
"200,000 ryo pay up little man" said Tsunade in a slightly agitated voice.
"hehehe call it a lone?"
"Only if you tell me your name and why you are here."
"I'm Aang the Avatar nice to meet you"said Aang
"uuhh were am I" the older boy said and the two girls were waking up.
"Sokka, Toph, Katara we crashed in a city called konohagakure"
"So what happened you three?" asked Kakashi
" We were attacked by the fire nation."
" Who are the fire nation and what is the avatar?" naruto's curiosity finally got the better of him
" the avatar is the embodiment of the elements who can bend them all with training."
" And the fire nation?"
" You are about to find out
A explosion rocked the tower and pieces of the outer wall went flying into the village
The fire nation has arrived.