The hot, hot summer of Tajimi has arrived, and Himeno, Mika, Naoko, and Touko have a blast in the river trying to catch eel!
Then suddenly a kappa appears before them and takes them down to Ryūgū-jō.
Inside Ryūgū-jō, a certain person in the form of their high school self is awaiting them...
Now please put on your hats!
!حسناً، ضعن قبّعاتكن
Und auf die Hüte!
Bien, ¡a ponerse los sombreros!
Bien, ¡a ponerse los sombreros!
Dans ce cas, à vos chapeaux !
Bene, indossate il cappello!
Agora, coloquem seus chapéus!
Надевайте шляпы!