Hoping to make a comeback after a bad scandal, an actress agrees to research a new role by taking a job as a secretary for a prickly attorney.

Every last Thursday of the month at an all-girls high school, the students of Class 2–5 cast their votes in a popularity poll. The results classify them into Grades A, B, C, D, and F. If they fall into Grade F, they become legitimate victims of school violence.

When mysterious alien spheres start invading the world, high school students are called upon to join the world’s first war against extraterrestrial forces.

The story of a girl who shuts herself off from the world and a housekeeping robot who goes to school against the backdrop of a near future.