Aoi Mutō returns from a long trip bringing fermented meat. She also brings Vibrio parahaemolyticus, El Tor, Shigella dysenteriae, Salmonella enterica and Plesiomonas shigelloides. After getting disinfected, Aoi brings Tadayasu to the UFO club room where all the members are sick and unintentionally breeding new forms of influenza with pigs and chickens.