Tobi just rips all the water from the enemy body -> Izuna goes back to the village and organizes the party. Uchihas have two events in life that define them as Uchihas. ONE: Awake Sharingan TWO: Fall in love with someone who can break them all bones.You are't the true Uchiha if you don't have these two events behind you. The whole clan will celebrate on this occasion. Tobirama will be the guest of honor. He didn't understant why Uchihas suddenly started to treat him like one of them.