I know that many people suspect that the straight haired statue at the valley of the end was Shodaime, but I have another theory...
We never really get a good look at the eyes, but the hair style could be that of a Hyuuga. Also, it was stated that the sharingan shares its origins with the byakugan. Many people already suspect that the spikey haired individual is an Uchiha, which I tend to agree with based on appearances. I won't go so far as to assume that it is Madara, because that would simply be an insane conclusion with no basis. Also, Kakashi said that Naruto and Sasuke's lives closely paralleled those two. Finally, the reason I don't suspect that it is Shodaime is because he only lived a couple of generations ago, but it seems that this valley had been at legendary status for a long time. Also, the impression given by the role of Hokage is that once they take up its mantle, each Hokage must always think of protecting the village as a whole, ignoring individuals and selfish goals; it doesn't seem to fit that a Hokage would leave the village all the way to the border of the fire country just to hunt down one man. This last part is just speculation based on the tone of the manga, so feel free to take it with a grain of salt.
Given that information...
I think that those two were brothers, and the Uchiha shown is one of the first. After attaining this new power (possibly through ill gotten means, based on Itachi hinting at "the true purpose of the sharingan") he decided to leave the village to attain more power. His brother, like Naruto with Sasuke and Jiraiya with Orochimaru, tried his hardest to stop him, but failed and was killed (maybe unlocking the first mangekyou). The result was the formation of the Uchiha clan. Over generations, Uchiha's intentions were forgotten or lost to all others but a few clan leaders, and they eventually worked their way back into the folds of the other Konoha nin.
Just a thought, but it seems to fit a little better than it being Shodaime. Its obvious from the number of Hokages and the way each clan contains their secrets (as if they've had more than 4 generations to work on those secrets) that the village of Konoha as a whole was formed relatively recently with respect to the age of individual clans. I just don't think the timeline is right.
Edit: if a mod could change the title to include [manga] it would be much appreciated.
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