Aika transfers into the prestigious S-class at a nationally renowned academic high school, only to fall completely under the control of Toni, the dominant teacher who oversees all aspects of education. In this class, students are divided into strict hierarchies based on exam results, with top performers designated as "Kings" and the lowest as "Rats." While high-ranking students receive special privileges, those at the bottom are subjected to fixed status and forced learning through brain-targeted narcotics. Due to poor academic performance, Aika is branded a "Rat," enduring intense training and extreme pressure to study. This work depicts the harsh school life of a big-breasted schoolgirl under complete domination, restraint, humiliation, rape, and sexual slavery.