Their group is called "Panache!", and the concept behind the trio is that it's a mix of 2D and 3D—in short, the concept is based on these girls bringing the 2D world to life with their cosplay.
The first Panache! single, "Kirameki Miraizu", will go on sale later this year, making these three—as far as I know—the first cosplayers turned major label recording artists. This also shows the cosplay can be more than a jumping off point for bikini modeling and video game even appearances—not that there's anything wrong with those professions!
Above, there's a look at how the trio brought Konami's love simulator Love Plus to life at last winter's Comic Market. Below is the official official Panache! publicity shot.