A friend of Ratonhnhaké:ton, from the same village. The two boys were the same age, and members of the same clan - making them cousins, though the connection may have been somewhat distant. The boys were inseparable throughout their childhood, with Kanen'tó:kon being the more conservative of the two - that is, Ratonhnhaké:ton would be the one to get them in trouble, and Kanen'tó:kon would try to talk them out of it.
Of course, after Connor left to become an Assassin he and his old friend drifted apart - sometimes that can happen when one of you becomes an Assassin - and they formed rather different views of how their village should participate in the war. While Kanen'tó:kon originally supported Connor's idea that the village stay neutral, after seeing the protection offered to other Nations by both British and French, he began to reconsider. Eventually he argued for the village's joining the war - generally on the side of the British, the allies of many other Kanien'kehá:ka.
Their disagreement came to a head when Kanen'tó:kon confronted Connor with the knowledge that his Loyalist allies had planned on attack on their village. In the ensuing fight, Connor was forced to kill his friend. So annoying when that happens!