The Japanese government has established the Tokyo Metropolitan Advanced Nurturing School, dedicated to instructing and fostering the generation of people that will support the country in the future. The story follows our beloved quintuplets and MC protagonists as they're appointed to Class D, where the school dumps its inferior students, widely considered "defective." After our main protagonists meet by chance, the situation suddenly changes as they get involved in various affairs, and the thought of an ideal normal high school life scatters, embarking on an interesting conflict.