Red Blood Cell is being chased by a germ! The one to come to the rescue is a masked Monocyte. Apparently, they are also part of the White Blood Cell family and a type of Immune Cell. There’s no way Red Blood Cell could be attacked by bacteria twice in one day, but she encounters another one on her way to the nasal cavity. The germ turns out to be Staphylococcus Aureus. They usually just exist on the skin and pores. But this time, they have a secret plan. What could it be?

An incident has occurred in the body! The Immune Cells rush to the scene and fight the cells infected by a virus. An Ordinary Cell observes this everyday scene with a bored look on his face and says to himself, "I want to heroically save somebody and have them say to me, 'Thank you for helping me.'" A group of mysterious bacteria appear in front of the Ordinary Cell and...