Paired together in their underwater NEEMO training, Mutta and Kenji seemed to be a perfect team - a combination that would take them all the way to the Moon. At least, that's what they thought....
Having been informed that, in fact, only one of the two of them will be selected from their team for the next lunar mission, the atmosphere suddenly changes markedly, and while Mutta seems to almost instantly resign himself to having no chance against Kenji's abilities, Kenji has clearly decided that nothing is going to stand in the way of his goal. From the warm friendship the two of them shared a cold war of sorts grows, with Kenji taking the lead in a bid to cement his place on the next lunar mission while Mutta flounders in his own worries and self-pity.
Such is the extent of Mutta's self-doubt that he immediately cedes plans to built a lunar telescope into the team's moonbase design after Kenji suggests that it should be cut alongside other elements of their plan to ensure that everything is finished on time. With the pair avoiding each other, Mutta continues to wallow in his worries until a combination of a discussion with senior team member Andy and a swarm of Barracuda awaken him from his malaise - with Andy discussing how he too was once burdened by the weight of similar worries about making it into space before deciding not to think about it and throw himself into his work again, Mutta suddenly sees a path clear in front of him with regard to what he must do.
All of this combines into another wonderfully character-driven episode of Space Brothers - having spent so much time building up Kenji and Mutta's friendship over the course of the series, it makes this cooling of that friendship all the more affecting while still playing off the natural drama which comes via the incredibly difficult selection process for lunar missions. Its current underwater setting might not quite have the flair and excitement of space itself, but it's serving as a perfect staging ground for another bumper helping of what makes this series what it is.