Adachi's kohai from middle school who transfers to Adachi's high school. Known as "The Bloody Pantheress", she was a Yankee and Hana's right hand man back in middle school. She is still very devoted to Adachi, has been ever since Adachi saved her and they became friends. While Adachi has reformed herself to become a good student, Himeji on the other hand still acts like a delinquent and believes that Chiba and Shinagawa are her gang subordinates.
She has a bad relationship with her family because she is adopted, and when she told them that she wanted to move to Adachi's school, they kicked her out of their home. Adachi took her to live at her house after finding about it, and after Himeji had spent a few nights sleeping on Shinagawa's floor. She appears to have a crush on Shinagawa and like Hana, has very strange way of thinking. Though she sometimes gets mad, the madder she gets, the more other people think she’s cute. She secretly owns a cat, loves housework, and actually has a lot of girlish qualities.