I would think if it was going to happen, it would of already happened. Though I would think gackt would jump on the opportunity because he has always spoken fondly of ayu. Though I guess if its what ayu would want to do. But with his music and hers. It could be a very good fresh song. Though it would most likely be one of her songs that they would sign together. Would be nice to have ayu do a duet with someone who was active when ayu was early on. But I do think gackt would have no problems. Maybe tweet his twitter too. Maybe tag both of them in post. It could be the duet of her next album