Sorry for bumping this thread.....but some reason, while I was searching for vids with the "Gundam SEED" tag on Nico, I came across an Amagami vid with said tag.
http://www.nicovideo.jp/watch/sm6569471
Now, at around 0:50-1:00 there's a line that could possibly be a reference to the series, but I'm not sure. Someone put a comment around there saying that it could be. Anyone able to verify this?