Artist: rikuness/Aqua
Theme: old fashioned chibi G (semi-Victorian)
I've always thought GACKT is a very old-fashioned kind of person, hence the theme. ^^
It's a fairly simple costume: dark blue overcoat with golden buttons and trim, a white semi-frilly cravat, blue contacts (to look more European), a small black top hat (he's tipping his hat in the pic; the perfect gentleman!), white gloves and pants and black lace-up boots. In his left hand he has a cane with a silver Moon symbol thingy at the top.

If he were to wear this for a concert, the concert would be at the end of his career. The concert's theme would kinda be like "time travel" and it showcases his entire career from the start to the end, so he would wear this at the very beginning of the concert (and in my mind, he would enter the stage in a horse drawn carriage with JOB and dancers as a fanfare ^^). Then it would go through his career and past concerts until the present. ^_^ (and again, in my mind, he'd exit the stage riding a... huge robot... GUNDAM!)
Anyways, that's my entry! ^_^ I hope it's okay that I took a pic instead of scanning (I don't like using the scanner...) ><