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....
There are plenty of factories on 
this island that were abandoned.
هناك كثير من المصانع في هذه
الجزيرة الّتي هُجِرَتْ
Auf der Insel gibt es
viele verlassene Fabriken.
Hay muchas fábricas
abandonadas en la isla.
Hay muchas fábricas
abandonadas en la isla.
Il y a des tas d’usines vides
sur l’île.
Sull'isola ci sono tante fabbriche abbandonate.
Afinal de contas, tem várias
fábricas abandonadas na ilha.
На острове хватает
заброшенных заводов.