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...
The rules behind their sequence 
are a complete mystery.
.قوانين تسلسلها تعتبر غامضة للغاية
Ihre Abfolge ist unmöglich vorherzuberechnen.
La nature de leur séquence
reste un mystère.
Le regole dietro la loro sequenza sono un vero mistero.
As regras por trás de
sua sequência são um mistério.
Принципы формирования ряда 
простых чисел не известны.