Haruka comes to teach at the Kokubunkan High School, a school renowned for both academics and sports. She is in charge of the senior class D with Yuko, the assistant teacher. However, she is shocked by and disapproves of Yuko's cold attitude towards the students. A mysterious boy called Toshio transfers from another school...he finds himself all alone after telling on some of his classmates. Meanwhile, Rio, who has just found herself a new boyfriend in college, brings some law-evading herbs to school. Yuko immediately realizes that Rio is being used. Haruka tries her best to help Rio without the school finding out. In the end, Haruka realizes that she cannot do this alone and so reluctantly asks for help from the "3 dark teachers": Yuko, Aya, and Sumire. -- TBS