That's THE [email protected]. It's a simulation game where players manage a group of young, Japanese pop singers. Originally an arcade game, the Xbox 360 and PSP versions have been big hits with Akihabara otaku. There are even concerts where the game's music is performed by the voice cast— those tickets fetch high prices.
A Japanese weekly magazine tries its best to explain the appeal with a picture spread of the attractive women who voice the characters. Ah, yes, these people can understand!