Crabs and Electricity are Important Natsuki and Atri go on a diving expedition to recover parts and resin from Ryuuji's family factory. Atri also catches a number of crabs. so everybody decides to have a barbeque. Later, Natuki and Ryuuji get into a debate on how to build the tidal power generator, with Natsuki admitting Ryuuji is more intelligent than he thought and Ryuuji apologizing for thinking Natsuki didn't care about others. That night, Natsuki wonders if a Humanoid is human enough, whether they should be treated as humans...