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....
Oh, I know that place! 
I always had my mom buy me some!
أعرف هذا المكان! كانت أمّي
!دائماً ما تشتري لي بعضاً
Ah, den kenn ich! Da hat mir
Mama immer welche gekauft!
¡Sí! Mamá siempre los compraba ahí.
¡Sí! Mamá siempre los compraba ahí.
Si, si !
Maman m’en rapportait souvent !
Ah, me lo ricordo!
Ah, eu sei qual é! Minha mãe
sempre comprava pra mim!
Помню её! Мама постоянно
там что-нибудь покупала.