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....
You're a robot. Why are 
you so happy about that?
أنتِ روبوت. لماذا أنتِ سعيدة بذلك؟
Warum freut dich
das als Roboter so?
¿Por qué te alegras tanto?
¿Por qué te alegras tanto?
Pourquoi t’es aussi contente ?
Sei un robot, cos'hai da rallegrarti tanto?
Você é um robô.
Por que tá tão feliz?
И с чего бы роботу радоваться?