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....
Doing this makes it feel 
like a cultural festival.
إنَّ القيام بهذا يجعلني أشعر
بأنّني في مهرجان ثقافيّ
Fast, als hätten wir hier
wieder Projekttag.
Esto me recuerda
a los festivales culturales.
Esto me recuerda
a los festivales culturales.
Ça me rappelle tellement
le festival culturel.
Questa scena mi fa pensare 
di essere al festival culturale.
Desse jeito parece até
um festival cultural, né?
Мы как будто
на школьной ярмарке собрались.