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....
But you two were shouting so loudly 
that we could hear you on the roof.
لكن كنتُما تصرخان بصوتٍ عالٍ
لدرجة استطعنا سماعكما من السّطح
Aber wir konnten eure Stimmen
bis rüber aufs Schuldach hören.
Pues estaban gritando tanto
que se los oía desde la azotea.
Pues estabais gritando tanto
que se os oía desde el tejado.
On vous entend pousser des cris
jusque sur le toit.
Però stavate gridando,
vi abbiamo sentiti fin sul tetto.
Но вы так кричали, что даже
на крыше было слышно.