Originally Posted by AkamaruChewtoy
Where to start?
1) Tsunade is indeed a Senju as she is the goddaughter of the first. Despite that lineage, Hokage is not a dynastic entity. Perhaps the Feudal Lords are, but Kages are chosen from ALL ninja and it is usually the strongest. Now, it appears that Kages come from families that have strong ninja in general, but it doesn't necessarily happen that way. The first two were Senju clan, then Sarutobi clan produced the third, Minato had no identifiable clan and then it went back to Senju. Kakashi also has not been given to a particular clan and he was nearly hokage - because he was one of the strongest.
2) Naruto has not be identified as Senju - he has no specified clan. Any link between him and the Senju has been hinted at only (and by Madara - if you want to believe a guy who doesn't show his face). There is no evidence that there is any link and if there was, I think Tsunade would have made some reference to it, especially during this conversation about remembering Minato, Kushina and Naruto.
3) It has already be said, but it is worth saying again: the Senju were a massive clan and they brought in a lot of other clans to create Konoha. They didn't all stick to the same clan - that's just genetically unhealthy. Plus, you'd get more diverse and strong nin by interbreeding - which I'm sure was known.
Finally, whether or not you want to reward people for reading between the lines and finding evidence for any type of theory is fine, but don't label it brave or forward thinking. It is still just grasping at minor straws and theories that don't hold up when you think about them and the evidence at hand. The words and panels are all we have and the only proof anyone can use - you can look farther if you want, but don't be surprised with people refute you using the manga as proof.
I agree with your #1 and most of your #2 eventhough I still personally think Naruto is related to the 1st or 2nd Hokage. What i dont agree with is when people say "if this were true somebody, Tsunade, would have said it already". U cannot tell Kishi that he should/would have made his character say something already just because u think they belong in the same discussion or should have been stated already. Still like u said, there is no real evidence to say Naruto is Senju, just like there was no real evidence to say Naruto was son of the 4th before it was revealed.
#3 I disagree with. As u said Senju were a massive clan. How did they get that massive? They safely interbred same way Uchiha and Hyuuga did. When Senju created Konoha, it was already a country with villagers. Senju clan and Uchiha clan were blood clans. How did they all become blood relatives from 2 different men? Well lets say the first Uchiha had 5 boys and 5 girls. The first Senju had 5 boys and 5 girls. Now those kids had babies with non Uchiha and Senju, yet their "genetic gifts" were still present in their offspring, kinda like how Haku's kekke genkai mother and normal father still produced the kekke genkai Haku. Now if those offspring had children with non Uchiha and Senju and those genetic gifts were still present, now second and 3rd cousin Uchiha and Senju could begin to safely reproduce without risking thinning out any more of their "genetic gifts" and without risk of genetic defects.
Sasuke had an aunt an uncle because they were either his father's or mother's sibling. All Uchiha were related by blood clearly, but some were directly related, same as Senju would have been. All Senju would be blood related, but the 1st only had 1 blood brother that we know of. The more they reproduced with "normal people" the less likely the offspring are to have those "gifts", or as strong "gifts" that once made them special.
Now when Konoha was formed and Uchiha kept safely interbreeding with 2nd and 3rd and 4th and 5th cousins that also had Sharingan to keep the Sharingan pure, Senju likely began breeding with common citizens, or their offspring were just less likely to become shinobi. For all we know, there may be dozens of shop keepers and blacksmith in Konoha with the last name of Senju, just no more shinobi left.
Konoha was created by 2 clans only, Senju and Uchiha. Other clan names could have come about the same way Senju and Uchiha branched off from the sons of the 1st Sage and strarted calling themselves Senju and Uchiha. Also, the female born Senju who married male commn citizens whose children would have their father's last name would have Senju dna, just not as pure and they wouldnt have the last name either.
If the 1st and the 2nd were brothers, there were definitely other Senju brother's and sisters. Say 1 family those other Senju siblings mainly specialized in allowing bugs to feed off their chakra and live in them, they could easily decide to branch off and start calling themselves Aburame. No longer trying to keep their "Senju physical gifts" as strong an as pure anymore, they wouldnt feel the need to reproduce with anyone special like Uchiha and Hyuuga, and Senju in the days when it was every clan for himself and a constant state of war.