 If you liked
Simoun
|
 ...then you might like
11-nin Iru!
|
A lot of science fiction falls into the trap of assuming that gender roles will work the same way even on settings that are completely different from our own reality. Simoun and They Were Eleven! both reject that assumption, giving their characters an opportunity to chose their own sex at some point in their lives. Each anime ends up doing pretty different things with that idea, but if you're interested in anime with some playing with and commentary on gender in an unreal setting, you'll probably enjoy them both.