Tobirama hated Madara, right? Everyone in the village knew that. Even Madara himself accepted the fact that Tobirama hated him even though he wasn't truly ok with it. But everything changed one day. The day Tobirama got badly injured in his mission and now that in the Konoha and hashirama tries to heal him, Tobirama keeps mumbling Madara's name in pain and desperation. Hashirama was confused so he told izuna to find Madara and ask him to come here. Now izuna comes back with Madara. Madara raises his eyebrows, takes a look at Tobirama then at hashirama. "What's going on?"