Kawai Mona-Kuroiwa Medaka ni Watashi no Kawaii ga Tsūjinai (Medaka Kuroiwa Is Impervious to My Charms)

The main heroine of the series. Mona is a beautiful and friendly second-year high school girl who is originally from Osaka Prefecture and had only moved to Tokyo the year prior. She prides herself on being the queen bee of the school, charming all the boys, until she meets Medaka. She then tries to win him over but ends up falling in love with him, although she denies the latter part. She occasionally reverts to her Kansai dialect when flustered. She is easily jealous of other girls who vie for Medaka's attention. (from wikipedia)