While not a true ecchi series, there are occasional sprinklings of fanservice in this otherwise dark sci-fi anime. Nipples are sporadically shown, staying true to the spirit of the manga.
Unlike most anime, manga has remarkably little aversion to casual nudity, even in very serious and dark subject matter. Only a few anime TV shows a season opt for nudity, and some companies seem to be categorically against it.
So when a manga has small doses of nudity, it’s fairly common for the anime side to remove it. For example, did you know the No Game No Life manga had openly shown nudity? But only barely so, and it was easy for the production company to ignore it. Same thing for Papakiki and many other well known shows.
I respect it when a company includes nudity even in very token amounts as a way of remaining true to the manga, even if that nudity kind of feels awkward or out of place. Sankarea did it, as did High School of the Dead and a few others. But in the last two years, it’s gotten pretty rare to see anime not avoid small doses of nudity in the source material when it is easy to do so.
The interesting thing is that none of these nude scenes from the anime were actually present in the manga, though this one is kind of close. The anime nude scenes occur in episodes one, five and seven, with some close calls in episodes two, six, and eleven.
The best nude scene belongs to the commander, Kobayashi. For most of the series we barely even see her face, but there was a lot to see in episode seven.