From the DrMaster outlet site:

At last a manga about cos-players, for cos-players! Ever since the school president established a casual dress code for the student body, Koromo has been wearing her cos-play outfits at her high school (although she claims they are her casual clothes). Follow the daily life of Koromo and her costume-designing best friend. Watch as she graduates high school, attends college, and ventures into the real world all in one fun filled volume!