A specific human's physique is in continual upheaval as a result of terrible lifestyle choices. With the abundance of germs, bacteria, and other substances, the duties of diverse cells become increasingly challenging and harmful. Sekkekkyuu AA2153 and Hakkekkyuu U-1196, as some of the unlucky ones who evolved in this chaotic environment, struggle to complete their duties—even if it means witnessing many of their fellow cells die in service. Hataraku Saibou Black depicts the challenges of cells as they fight to preserve the body's health in a setting substantially different from that of its parent narrative. However, the human situation continues to worsen, and whether or not these efforts will yield tangible results is dependent on the cells!