But Never The Same Way Twice

The Uzumaki siblings are direct descendants of well, the Uzumaki clan, taken in by the hidden leaf village, their parents swore loyalty to the sixth and future seventh hokage. Kaida and Hoshi were born with their parents hoping that their children would become the jinchuurikis' of the 12 tailed beasts*, with the hope that their children, once becoming the hosts of the tailed beasts, would make them more powerful and talented. But alas, Naruto Uzumaki had to break it to them that only the Uchiha Twins that were to be born that year could be the human sacrifice for the dragons. Deeply disappointed but understanding, they continued on with their lives, working as one of the most reliable medical-nins for their Uzumaki blood. The couple still told their children about their could-be fates as jinchuurikis', manipulating them into believing that their power--their fame was snatched by the Hokage's fateful partner's children. 

The two of them, a year after Kaida's entrance to the academy and a year before Hoshi's first day, they disappeared without a trace, leaving their parents and younger siblings behind. 13 months later, they show up once again, not saying a word about where they went or what happened. But with whatever happened between that year, they somehow got extremely powerful, getting perfect grades and perfect performances in the academy. Everybody believed their Uzumaki blood was the reason for their new strength, they beat everyone at everything--except for the 6 children of Sasuke and Hinata Uchiha.

and once again, they went rogue, in such a short time, they got back to the village and suddenly start terrorizing everyone--they were even suspected in a murder of a young kunoichi. Now here they were, in the valley of the end, being hunted by the two people they utterly hated. 

it was time for the awaited rematch--Uchiha vs Uzumaki in the valley of the end.

------
*will be explained in the next part of this.