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...
Hey, no fair!
!لحظة، ليس منصفاً
Hey, nicht fair!
Tu triches !
Ehi, non vale!
Ei, não vale!
Эй, нечестно!