Avatar: Great color, it looks kind of, grainy, but nice otherwise. I'd change the color of the border though. Perhaps a yellow.
Signature: I like it alot. It's cute, colorful, and very happy looking. The hand drawn sun is a nice touch, but I would change the background to an anime background. Perhaps the same one of where you got thos characters from. Font is a little small too.
8/10
Good work =D