Hashirama Senju, the First Hokage of Konoha, was one of the strongest ninjas ever and was hailed as the God of Shinobi. Obito Uchiha gained immense power as the Jinchuriki of the 10 Tails ...
Internal power struggles likely contributed to rising tensions. It is against this backdrop that the First Hokage, Hashirama ...
this could also be the reason why Kawaki had a different outfit in the flash-forward shown in the manga's first chapter. After Kawaki is possibly made the Hokage, he could change his attire.