Natsuki sets his heart on creating a tidal power generator that utilizes the ebb and flow of the ocean's tides. He dives back into the ocean to find some materials and salvages some resin from the ruins of Ryuuji's family's factory. As soon as he gets back he gets to work. As they are working, Natsuki and Ryuuji exchange heated opinions over how the generator should be built. Atri intervenes and the two guys become closer friends. Meanwhile, a suspicious-looking character peeks at them from outside of the school....
That means that you'll have 
light in the school, right?
هذا يعني بأنّك ستحصل على أضواء
في المدرسة، صحيح؟
Dann bekommt
die Schule wieder Licht!
Así habrá luz en la escuela.
Así habrá luz en la escuela.
et la lumière reviendrait à l’école.
Potrete accendere la luce a scuola!
Você vai conseguir
iluminar a escola, não é?
И в школе появится свет!
โรงเรียนก็จะมีแสงสว่างใช่ไหมคะ