I can't find a particular AMV I saw at Sakuracon some years back. It featured Naga singing a song with the words "Black Leather" a lot. I thought it had been a Joan Jett tune, but when I look up "Black Leather" by Joan Jett, the lyrics seem different. The video uses sound and sight to describe Naga in a dress when she was a little girl. There's nothing like that in the Black Leather song lyrics. DOes anyone have any input that would shed light on this?
There's a contest archive, but it's only viewable for people registered on the Sakura-Con website, which has its registration closed. What's the anime called and maybe I can help you out. I'm assuming it's not Naga since it sounds like you're talking about a character and I don't know who that is.