Manga Wortenia Senki

Mikoshiba was quietly studying in high school when she was suddenly called into a world where war was going on. She suspected something was wrong with her own summoner, who turned out to be an extremely evil emperor. She uses her own knowledge and powers in martial arts to kill some of the emperor's important subordinates and then escape.
Here she manages to save two twin sisters from being kidnapped, and they turn out to be witches and become Mikoshiba's henchmen. In such an interesting company, she begins her ascent to the imperial throne.