Timebomb Teacher

Azusa Tsukumo, a plain and timid chemistry teacher, was living a dead-end life in the countryside. But everything changes when her younger sister, Ruka, goes missing. Chasing the only clue, Azusa heads to Tokyo and there, she encounters a lone yakuza. To reclaim her beloved sister, Azusa plunges into a world of violence, wielding chemistry as her weapon, what fate awaits her?!