Tadayasu teams up with Oikawa to find the truth about the mysterious door while Haruka is warned by her father that the time is running out for her to wrap up her research and fulfill the promise she made to him.

Sawaki and the others bid farewell to Marie, but before departing, Sawaki have the microbes there to write a message of encouragement to her and her father. Haruka returns to confront her fiancéé just to find him ill. As she tends to his condition, the two finally comes to terms.

It's the first day of Tadayasu and Kei's university life. Tadayasu shows off his ability to Professor Itsuki and Haruka. The talent show is cut short when Tadayasu spots fructivorans in the air.

Before returning home, Sawaki and his friends meet Marie once more and learn that the messages left by the microbes helped her family to resolve their differences and move on with their family business. Finally back at Japan, Hasegawa wonders about what she should do from then on, as with her engagement cancelled, there is no reason for her to remain at the university, but Sawaki encourages her to move on with her carreer not for obligation but for doing what she really wants to.

Haruka asks for Misato and Kawahama to take her back to Japan, but with her fiancéé's escorts looking for her, they decide to go separate ways to evade them. Sawaki confronts Marie about her relutance to inherit her family's winery despite she is so enthusiastic about her life on it, while Misato and Haruka manage to evade her pursuers and surprisingly end up having some quality time together.

Professor Itsuki divides the students into two groups for the creation of different fermentation products. Oikawa discovers a secret entrance which is later no longer there. She begins to suspect that the others are hiding something from her.

Tadayasu and Kei follow the fructivorans and find a spilled tank of spoiled sake. They meet the perpetrators Kaoru and Takuma who invite them to their dorm room.

Tadayasu confesses his secret to Oikawa, but she does not believe him at all. Haruka is picked up by her father who leaves her letter of resignation in Mutō's hands. While Haruka embarks on a trip with her fiancé against her will, the students start to make preparations for the upcoming Harvest Festival. Oikawa and Mutō refrain from telling the boys the truth about Haruka's sudden abscence.

After not seeing Kei for a while, Tadayasu discovers that he is working at Hiyoshi's liquor store, and on top of that is cross-dressing as a Gothic Lolita. Unexpectedly, Kei kisses Tadayasu, and afterwards Tadayasu discovers that he cannot see microbes anymore. This has happened before, but Haruka finds out and confronts him about the loss of his ability.

The Harvest Festival begins. Misato and Kawahama mount a Tequila stand resorting to suspicious tactics in their scheme to win the Grand Prize, while leaving Tadayasu and the others to attend the customers by themselves. Meanwhile, Professor Itsuki makes his move in an attempt to bring Haruka back to the University.

Tadayasu becomes disgusted when he sees a man covered in microbes. Professor Itsuki asks everyone to buy liquor at Hiyoshi Liquor Store near the school. Tadayasu discovers the owner is the microbe monster who brews delicious sake.

The first years are invited on a tour around the campus and a picnic. Tadayasu spots harmful bacteria in the food and saves everyone from E. coli food poisoning.

The spring agricultural festival has started, and that means that during this time, the campus is closed and students have to exchange real money for school money, but when the festival ends the school money is worthless and cannot be exchanged back for real money. There are also many special rules related to the event that students have to find out on their own.

Professor Itsuki holds a celebration for Kaoru and Takuma getting part-time jobs, and during this party introduces everyone to the foul-smelling surströmming. Later, Haruka is summoned to a private dinner with her father and fiancé, but gets Kaoru and Takuma, who had actually been working at the restaurant before getting fired by Haruka minutes before, to think of something to get her out of the dinner. They call Tadayasu who brings a can of surströmming; once the can is opened, Kaoru and Takuma take Haruka out in the confusion and go to a bar.