The second closest bloodline to the SO6P is.

[EliteKage]

After Hashirama and Madara
Tobirama and Izuna

 

[Transcendence]

You... You don't say?

 

[Sir Blades]

Oh my Gawd, you have enlightened me, praise the Lawd.

 

[Uchihabrat1560]

Nope..2nd closest is hashi and madara.. since Tajima and Butsuma are intro'd now..

 

[Omnipotent]

Hashirama and Madara are the second closest out of those that we know.

The Younger and Elder Sons are the closest by far.

 

[Silent Zetsu]

I totally didn't know that!!

 

[SilverSlick]

Tobirama is SO6P incarnate. Oh forgive me Lawd, saying such disrespectful things as that would be an insult. Tobirama is the ruler of the NV.

 

[EliteKage]

I totally didn't know that!!

Well your welcome..

 

[Champ]

Since Rikudo was Uchiha/Senju in one body they are his direct descendants, then you have the Uzumaki's who were the Senju distant relative.

 

[zinescience]

naruto nd sasuke

 

[yes iam Sakura chan]

Tobirama is SO6P incarnate. Oh forgive me Lawd, saying such disrespectful things as that would be an insult. Tobirama is the ruler of the NV.

^^^this just made my day .thank you