The first semester has come to a close, and the Ikeda lab is having a party where everyone's bringing what they like to eat and drink. They're having fun, playing games like the "prime number Yamanote line game," when a drunken Himruo finally does a certain something with Yukimura... And even Kanade ends up drunk... On the other hand, the mood quantifier obtained through the previous round-robin kiss experiment has progressed their research tremendously, and in order to gather more data, Yukimura and the others use fairy tales such as "Snow White," "Kaguya-hime," and "The Crane Returns a Favor" as references, but...
A number which cannot be divided 
by anything but one and itself.
.هو عدد لا يقبل القسمة سوى على واحد أو على نفسه
Eine Nummer, die nur durch 1
und sich selbst geteilt werden kann.
Un número que solo
se divide por sí mismo y uno.
Un número que solo
se divide por sí mismo y 1.
Uniquement divisibles
par un et par eux-mêmes,
Numeri che possono essere divisi 
solo per uno e per se stessi.
Um número que só pode ser
dividido por um e por ele mesmo.
Число, которое делится на единицу 
и на само себя.