Board Thread:Naruto Discussions/@comment-43638386-20190828024709/@comment-43638386-20190829073506

But we don't really know anything about the other places where the summoned animals live, nor about their ways. How did Hanzo first signed a contract with the Salamander? or Kisame with the Sharks? Their places are also secrets. In the anime (not canon, I know) according to Hiruzen in order to make a contract you need to have a natural affinity with that animal. Jiraiya was the first in Konoha to make a contract with the toads and Orochimaru with the snakes,obviously Tsunade has an affinity with the Slime since its perfect for her healing techniques, Kisame has affinity with the sharks and Hanzo's Salamander uses poison just like him. Its also never stated that toads and snakes are the ONLY ones to teach sage mode, it is said they are KNOWN for it, we all need to understand that the story is told from Konoha's shinobi point of view so they will focus on summons from Konoha's shinobi and Konoha's knowledge.