Well I just noticed this in a thread, someone pointed it out ( thank you whoever that was, don't come in here and be a crude moron. ) and I wanted to make an actual discussion on it.
It was stated Madara and Izuna both killed their closest friends to gain the Mangekyou Sharingan. Madara's best friend is Hashirama, so I'm really starting to believe Kishi has left quite the plot hole gaping there. Madara didn't kill Hashirama or didn't plan to until the rise of the villages or the incident that we are about to see. He also wouldn't have been able to, so this plot hole remains quite clear until an explanation.
TL;DR It was said they killed their best friends to gain MS, Madara didn't kill Hashirama.
It was stated Madara and Izuna both killed their closest friends to gain the Mangekyou Sharingan. Madara's best friend is Hashirama, so I'm really starting to believe Kishi has left quite the plot hole gaping there. Madara didn't kill Hashirama or didn't plan to until the rise of the villages or the incident that we are about to see. He also wouldn't have been able to, so this plot hole remains quite clear until an explanation.
TL;DR It was said they killed their best friends to gain MS, Madara didn't kill Hashirama.