Hataraku Saibou

Inside the human body, trillions of cells work without rest, each performing a job that keeps their enormous shared world alive. Red Blood Cell AE3803 begins her career delivering oxygen but has an unfortunate talent for getting lost in passages she is supposed to know. Elsewhere, White Blood Cell U-1146 patrols the body and eliminates invading bacteria with ruthless efficiency.

Oxygen deliveries, wounds, influenza, allergies, parasites, and countless other problems turn ordinary biology into full-scale emergencies for the body's inhabitants. Platelets rebuild damaged areas, immune cells fight intruders, and every other worker handles a task that may seem small but cannot be neglected. Human life continues because all of them keep working, even when the person they protect has no idea what is happening inside.