Sawaki Tadayasu, a new first-year at Agricultural University, can see microbes; when he spots massive numbers of microbes pouring out of the ground, he suspects that a missing student, Hasegawa Haruka, might be buried there.

Sawaki traces Hiochi bacteria to a room where two upperclassmen, Kawahama and Misato, are illicitly brewing sake.

Kawahama and Misato begin to cultivate caterpillar fungus to make money and Professor Itsuki celebrates the construction of his new fermenting cellar with a sake brewing demonstration.

Professor Itsuki sends Sawaki and his best friend, Yuuki Kei, to steal vegetables from a university farm.

Sawaki encounters a man named Hiyoshi Kikuji, a friend of Professor Itsuki's, who is covered from head to toe in microbes.

Mutou Aoi, who once held the title of Miss Agricultural University, is ready to take it easy now that she's back in Japan; then Sawaki spots a microbe on her that's infamous for causing food poisoning.