Tousuke Rokudou is a timid first-year student at Amori High, a school notorious for its aggressive delinquent population. Constant bullying leads him to use an ancestral scroll inherited from his late grandfather, which he believes will protect him from harm. Instead of granting him martial prowess, the scroll places a mystical pentagram on his forehead that causes any "bad girl" (delinquents, criminals, or those with antisocial tendencies) to fall instantly and unconditionally in love with him.

The central journey of the series is Rokudou’s transformation from a "wimpy" victim to a respectable leader.