You can change both the front and back hairstyles. It'll make (my character) Rabz' Tousled Pigtail style look a bit different. Speaking of Rabz, I plan on playing as her in the month I buy SSFF, after that, it's two of my favorite characters from "Trendsetters", Brienne from the Fashion Contest, and Clara from Downtown, since I'll cycle between SST and SSFF.