Author's note: First, a big thank you to lord_mune for illustrating this story.
Then, this story isn't historically or anthropologically accurate. Don't take it too seriously and don't get offended if something is wrong (do point it out to me, I like learning new things). Now, I did some research on Native-American customs and I had heard of some stuff. All is not to be believed equally though.
About marriage: in certain tribes, it was custom for the groom to offer presents to the bride/bride's family and if they were accepted it meant the proposal was accepted. Now depending on the kind of tribe, the groom would take the bride in his family (hunter tribes with a more patriarchal system) or would go live in the bride's family (agricultural tribes with a more matriarchal system).
About homosexuality: I read a few things like homosexual people were considered to have more spiritual power or something. Fucking a guy in the ass didn't make you gay and was only considered a real proof of masculinity. Boys were encouraged to "learn homosexuality" because of the whole spiritual thing. It was considered good luck and a great honour to have homosexuals in a community. But all that was read on the internet and I don't have any proof so it might be myth. What I did read that I had already heard somewhere else was that gay couples were usually treated like a heterosexual couple by pretending that one of the partner was a girl (dressed up as one and all). Then again, maybe some tribes did it, maybe no tribes did it (who knows, all of them might have done it) so don't take it at face value.
About this story: Yahto is a Sioux name that means blue. Yahto is blind because he has cataract which kind of makes your eyes look bluish, hence the name. Nanka should have been a name from somewhere only I can't find it again. François is obviously a French name. It is possible that at some point I was going to make Yahto's tribe Huron from Canada (they used to live in longhouse too, making it even more plausible) I even think that the French deported the Huron at some point though I am not sure. The story further up with Winnabojo and the Thunderbird is taken from the legend of how the silver birch came to be. I do not know which tribe this legend come from. The story was part of a book called 'Mille ans de contes' and has a lot of tales from very different origins. The story was just presented as being native-american.