@Smokron: No, it's three heroines, all three are differently styled gyaru. The idea is we see how each of the three grow closer to the unnamed Otaku.
Kinjo, a JK gyaru or kyogyaru (the most classic gyaru), is the most likely so it's a safe bet she'll come out on top.
Himekawa, an agejo gyaru (the most fashionable gyaru), clearly dislikes him but is meant to be the most fun since we'll see how she goes from the negatives to the positives.
Otomore, an ane gyaru (the most "rogue" looking gyaru) is completely unknown, hence the ?, but that's also the fun of it. It's unlikely she's an actual gyaru, but given the title, it seems appropriate.
(This is all "Chapter 1" stuff, meaning there's no spoilers)
(Also, don't be impressed. This was just a quick skim through Wikipedia)