Ayane's First Appearance 
Just wanted to point out that Ayane's first appearance was in DOA2. She may have appeared in DOA1 as an unnamed trainning dummy that looked like her, but DOA2 was when she was first playable and given a name.  Also unlike what this article suggest, she was never in the NES Ninja Gaiden, I recently played them all to see what I missed out on and never saw her, so I edited this article.  She does however make a cameo appearance in the xbox Ninja Gaiden game, so that may have been where the mistake was made, although DOA2 came out years before Xbox NG.66.183.46.232