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...
When did you get here?
متى أتيتِ هنا؟
Quando sei arrivata?
Quando você chegou aqui?
Ты давно здесь?