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....
If you insist on continuing, 
my Rocket Punch will go flying!
إن أصررتما على الاستمرار، فإنّ
!لكمة الصّاروخ خاصّتي ستقذفكما
Wenn das hier so weitergeht,
kriegt ihr meinen Rocket Punch zu spüren!
Si continúan, tendré
que recurrir al puñetazo cohete.
Si seguís, tendré
que recurrir al puñetazo cohete.
Si vous continuez, je vous envoie
mes poings dans les dents, attention !
Se non vi decidete a smetterla,
Se insistirem em continuar,
meu soco foguete acabará com vocês!
Если не успокоитесь, отведаете моего
Ракетного удара!