Harahara-sensei

"I won't run away anymore. Even if I have to face against yakuza to whom money is everything. As long as it means I can get my sister back." After having her dream of working in academia ruined, Azusa now works as a teacher in the countryside and her days are spent putting up with the terrible treatment she receives from both her students and colleagues. One day, she came to learn that her younger sister Ruka, the only blood relative she has left, has gotten caught up in some trouble in Tokyo. What will Azusa do now that she's faced up against suspicious members of the underworld society? Here's the start of a hardboiled action series! (Source: Shueisha, translated)