Itsuki, Nayuta, and Miyako have a hard time dealing with the cold and head down to Okinawa. The next day, they visit a remote island so Itsuki can do some research and Nayuta decides to flail around naked in the water. Miyako is awed by what she's seeing and eventually jumps into the water naked, as well. Two days later, Itsuki is invited by his illustrator to go to Hokkaido, where they try various local cuisines. However, Itsuki finds out that Setsuna had been ignoring a deadline...
But, Sensei, how's a fish supposed 
to have sex with a human?
Erklär mir mal, Sensei, wie fickt ein
Fisch eigentlich mit ’nem Menschen?
Maestro, ¿cómo puede tener sexo
un pez con un humano?
Maestro, ¿cómo puede fornicar
un pez con un humano?
Mais comment un poisson
et un humain couchent ensemble ?
Però,maestro, come può un pesce
fare sesso con un essere umano?
Mas Sensei, como é que um peixe
 vai fazer sexo com uma humana?
Но, проясните мне,
а как человеку с рыбой детей делать?