I'm personally a Yuuichi x Nayuki shipper, although they are cousins, to me that doesn't matter. For anyone that has played the original Kanon VN, that in the Nayuki route of the story, Yuuichi does show more affectionate feelings towards Nayuki than in the anime and the message he recorded on one of her alarm clocks proves that he does love her. Considering Nayuki is a kind and gentle girl, she would be the kind of girl Yuuichi could always confide in, her sense of humor would always put a smile on Yuuichi's face.
So, I would like to hear your views on why or why not you would support Yuuichi and Nayuki as a couple.
Well, it may sound weird, but I've always shared the opinion that if something is marked as forbidden then it is worth trying twice the effort. In case of Kanon we're not talking about something extreme (like in e.g. Koi Kaze) but nevertheless it's a family matter.
I played the vn, watched both anime series and I'm 100% sure Nayuki and Yuichi are the best match. She's a great support for him, gentle and bright, and puts all her heart to club activities in which she acts as the captain. Most of all, Nayuki's a type that doesn't want to hurt anybody, especially someone as dear to her, as Yuichi.
I think that the producers pretty much underestimated her role in anime (mainly 2006 ver.) or tried to implement some part of her story and then do some unreasonable bad end at finish (the horrible farewell kiss in 2002 ver.). Poor Nayuki. :D
Well they make a cute couple even when they are cousins and yeah i will be ok if i saw her alternate ending but i don't mind kanon's real ending because i'm already yuuichi x ayu shipper so it's ok both ways to say the truth yuuichi matches every girl my favorite choice for him is mai and then ayu after that nayuki and makoto or shiori so every choice is ok