Kurosaki Mafuyu was a juvenile delinquent and head of her gang before her subsequent arrest got her expelled from high school. Now that she's transferred to a new high school, she's determined to become an "ultra-shiny, super feminine high school student." But with a new friend like Hayasaka-kun and a homeroom teacher like Saeki Takaomi (who may be more than he seems), will Mafuyu really be able to live a girly-girl high school life!?