Aoi Muto is having a bad day. First, she secretly drank Professor Itsuki's beer, only to find it as sour as vinegar. Then, Kei Yuki asks her for advice about the Hiyoshi sakaya, but it involves Japanese microorganisms that Muto hates without actually knowing them. Determined, as a true researcher, to overcome her prejudices, she will explore the world of craft beer. And she will decide to help a microbrewery by organizing an Oktoberfest at the agricultural university!