Nine Muses are taking a unique approach to their comeback. The ladies are splitting into two separate unit groups --the Dark Muses, with a sexy, mature concept, and the White Muses, with a fresh, innocent style-- to promote their new single, "Dolls," which drops on January 24th. The official teaser photos for the Dark Muses were unveiled earlier today, and they're every bit as chic and sultry as we'd expect from a group originally billed as K-pop's "Supermodel Idols."

The Dark Muses are made up of Kyungri, Eunji, Hyuna, and the group's latest addition, Sungah -- very nice, but why no Leesem? It's hard to imagine the Nine Muses' towering glamazon as one of the virginal White Muses. We're also trying to figure out just how this whole unit thing is going to work. Will they be performing the same song separately with different choreography and the whole bit, or will they all be on stage together? After School famously did their own sweet vs. sexy sub-unit promotions back in 2011 with their Red and Blue unit groups, but they had completely different songs. It'll be interesting to see how Nine Muses do it with just one single between them.

Check out the official Dark Muses "Dolls" concept photos below.