Madara managed to get the elders to agree to peace exactly after the fight which left his little brother injured. He managed to get peace for his people on time for Hashirama to heal his brother.
And thus Konoha was founded.
Little by little the shinobi started feeling safe in the village and were comfortable around each other.
Which brings us to the present: The two founders and their two brothers were preparing to enter the local hot springs. It was the Uchihas who were ready to go inside first while the Senju were watching.
Madara was about to enter the hot spring when he heard a gasp from behind. When he turned to look behind himself he saw Hashirama gapping at his soulmark while pointing at it. Madara's eyes narrowed, „If you even think something bad about my soulmark I will skin you with a rusty fork." It wasn't an empty threat. He does have got the needed skills to do that.
His soulmark was of two dragons dancing in perfect harmony. One was made of black fire and the other was made of crystal-clear water and both had red eyes.
„Ahh. No, no, no." Hashirama flailed, „It's not that there is anything wrong with your mark or anything, it's just that I recognise it." Nearly shouted the Hokage.
Madara hummed before relaxing his face and entering the spring with a satisfied sigh while Izuna watched the whole exchange. The younger of the Uchihas exchanged a glance with Tobirama who kept his mighty poker face and continued to rid himself of his clothes, careful to keep his back from being seen and entered the spring last with a relieved sigh, the hot water already helping relax his tense muscles. The albino settled on telling his soulmate about his matching mark after one of their weekly spars. After all there was no need to hurry and that could very possibly destroy whatever their relationship was.
They were laying on their backs, panting from sparring for the better half of the day, knowing that the day after they would have more than a few aching bruises and scratches.
„I am your soulmate." Blurted out the albino.
„I kno-" Started the head of the Uchiha clan before he turned to Tobirama with wide eyes, „What?!"
Tobirama realising what he said, covered his mouth with his hands and made a sound of suffering.
„The hot springs. You have known since then and you say something now?" Asked the Uchiha clan head, a wounded look in his eyes and Tobirama could easily feel the displeasure, sadness and deviation in his chakra.
„I am sorry... I didn't know how to bring it up." The albino cringed after finishing. In reality he was afraid that he would be rejected and thrown away like the trash the better part of the Senju see him as because of his albinism.
After a few minutes of silence and Madara studying Tobirama, he asked, „What are you planning to do now? I am planning to follow Uchiha traditions."
That shocked the Senju. He wasn't hated or screamed at. That went against their normal way of communicating with each other. Madara seemed to be oddly calm but he knew that he was a nervous wreck.
„And what are the Uchiha traditions concerning soulmates?" Asked Tobirama when curiosity won.
„It is to court the other person to see what the nature of their relationship is." Replied Madara with a pointed look as if to question his intelligence.
Then the Uchiha got up and pulled up his soulmate with a heart winning smirk, „Well, at least my soulmate is handsome. I might have to chase the ladies away." He said, earning him a choke.