Things have been peaceful for Red Blood Cell when suddenly an abrasion occurs before her eyes. The White Blood Cells (Neutrophils) arrive to battle the bacteria and viruses invading through the wound, but they struggle against enemies like Staphylococcus aureus. Will the White Blood Cells (Neutrophils) find a way to defend this body?

A mysterious cell wearing a stylish hat appears before the regular cells, who are bored with just the same (cell division) work repeatedly, every day. This mysterious cell lures the regular cells into a mischievous scheme against White Blood Cell and Killer T Cell. The regular cells enjoy working out their everyday, pent-up frustration. But just who exactly is this cell wearing a stylish hat?