Haruna Tsubame, an inconspicuous high school girl, is always sensitive to people’s moods and keeps the peace in school. One day, she gets pushed to become the president of the student council by the people around her. Tsubame's encounter with a man who is a genius speechwriter, leads to a revolution in school. She struggles to change a school full of irrationality and dissatisfaction with the power of words.

These real-life mysteries explore the dark side of female connections and rivalry: the inner workings of cutthroat cliques, vicious backbiting and cruel intentions. Who are the queen bees and the wannabes -- and who thrives on jealousy and gossip? Sometimes these dynamics lead to shocking acts of psychological and physical violence.

High school student Hoshi Izumi loses her father suddenly in an accident. One day, Sakuma, the waka gashira of a small and weak Yakuza gang in Asakusa - the Medaka Gumi - pays Izumi a visit along with the gang members. The death of their former kumicho (Boss) puts Medaka Gumi on the verge of a breakup. Therefore, Sakuma begs Izumi, the former boss's only distant relative left, to succeed to the kumicho position. Izumi is taken by surprise and keeps refusing at first. However, she ends up becoming the 8th kumicho of the Medaka Gumi! The police tell her that her father's death may possibly be a homicide case. There's also Mayumi, a mysterious woman staring closely at Izumi's father's photograph at his funeral. The situation becomes complicated when the drug-dealing vicious yakuza, Hamaguchi Gumi, comes into the picture as well as Sandaiji Hajime, a politician whose public stance is to eliminate drugs.