The only times when Tobirama smiles is always because...

[EliteRamenNinja]

Naruto.

Confirmed: Naruto is the son Tobirama always wanted.

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[SanjiNL]

Cool story bro. Its obviously because Naruto reminds him of Hashirama.

 

[EliteRamenNinja]

Cool story bro. Its obviously because Naruto reminds him of Hashirama.

Confirmed: Tobirama always wanted a second brother like Hashirama.

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[Uchiha Josephus]

Confirmed: Tobirama always wanted a second brother like Hashirama.

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LOL! Well I suppose you are correct.

 

[sulanis]

I think Tobirama is just proud to see that the will Fire is instilled in Naruto so strongly. Oh and yes Naruto does remind him of Hashirama.