Red Blood Cell gets her very own rookie to train, but her nerves make her even more inefficient. When a crisis strikes, however, she knows her job.
Red Blood Cell has been assigned to train a rookie Red Blood Cell. She resolves to "show her what a dependable senpai I am" but she keeps losing her way, and getting yelled at by other cells, so it's not going very smoothly. Just then, a major incident rocks the world inside the body.