Is this even a cosplay if those clothes are officially on the novel and anime itself? hell those pattern aren't even index's!

In addition to that, the design on the gold isn't the same either. With that, I removed the index-related tags.

Right, it's something from ZnT, it is just similar to Index at a glance post #980590 example... and someone just bumped it onto the front page from 4 months ago.