Hinako Nakayama, the protagonist in Kenka Banchou Otome - Girl Beats Boys, spent her entire life in government-run orphanages without any knowledge of her family's existence. At the cusp of her high school journey, Hikaru, who claims to be her twin, suddenly appears. According to Hikaru, they both belong to the Onigashima yakuza family with him being the heir to their leader. Hikaru wants Hinako to take over his position at the all-boys Shishiku Academy. Can Hinako protect her brother, find love, and claim dominance over the school?