Hazuki Oikawa is introduced. She comes to Kaoru and Takuma's dorm room and kills the bacteria they were planning to cultivate. Everyone is summoned back to the lab where Professor Itsuki and Haruka show them how to make sake for educational purposes.

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.

It is the third day of the spring agricultural festival, and the students are forming a resistance in order to end the festival. At 4:00 PM, the students charge towards the front gate to engage in a battle, and during this time, Kaoru, Takuma, and Tadayasu work together to take down the robot in front of the gate and effectively end the festival. In return, they get 100,000 school yen which they use to get Professor Itsuki's aphrodisiac, they try to get one of the girls to take one but Haruka foils their plan by using all of them on herself, seemingly immune to their effects. Oikawa and Mutō get some from the professor themselves and sleep with each other as a result.