Yuki Amami plays Maya Akutsu, a sixth-grade teacher who dresses all in black and is repeatedly referred to as "oni sensei" (the teacher from hell), when, in fact, she seems to be an ultrarealist at heart. The drama focuses on a year in her classroom and, particularly, the effect it has on 12-year-old Kazumi--a nice but mediocre student whose parents want to send her to a private secondary school.

Akutsu-sensei accomplished this feat by introducing a test-based rank and privilege system on the first day. The highest scorers on the Monday morning test get their choice of seats and other perks while the two lowest scorers are burdened with all the chores for the week from blackboard and toilet cleaning to serving lunch. The system also disallows toilet breaks during class because this reflects an inability to manage one's own schedule.

Kazumi gets the first week's work assignment along with the class clown, a warmhearted boy who is not nearly as silly as he acts. The child actors in the series are all likeable pros who give realistic portrayals of the wide spectrum of an average classroom from the isolated serious students to the sophisticated girls who think they already know what life is all about. Akutsu-sensei lets them know immediately that they do not have a clue.

When the students protest her system and call it unfair, she tells them to open their eyes. In Japanese society, she lectures, those who work hard or have influence get all the privileges, and the lazy or less affluent end up with the leftovers. She says only six in 100 people can expect to be happy and the elite already have most of the advantages and access to the best medical care. She tells them that, as products of the public school system, they will have to scramble to get anything at all, and most of them will end up as "bonjin" (ordinary people), to whom those on the top will be happy to leave the soldiering and service-sector jobs.