An arcade and console raising simulation game, The Idolmaster 2 follows the lives of girls trying to realize their dreams of becoming famous. The game was first released exclusively in Japan by Namco on the 26th of July 2005, and later on Xbox 360 on the 25th of January 2007.
I’m pretty sure Tomia, Tasha, and Eki are there, but I’m not sure who the other girls are and which characters they are cosplaying as. Maybe someone can name them properly? Thanks to Kline for sharing this!