It's the same singer that sing most of Ar Tonelico songs for Shurelia and Jaqli?!
Piqued my interest too, that the singer might've done some sort of manga anthology at some point. It's not unheard of, Kitamura Eri, for example, draws manga. Couldn't find anything to the effect that it's the same person, though, but I'm not a fan so I wouldn't know. If anyone knows for sure I'd be curious.