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...
But wait... how come we can talk underwater?
لحظة... كيف نستطيع الكلام تحت الماء؟
Aber Moment mal …
Wir können ja unter Wasser reden!
Hein ? On arrive à parler sous l’eau !
Un momento... Possiamo parlare anche sott'acqua?
Mas... desde quando podemos
falar debaixo d'água?
Минутку... Как мы говорим
под водой?