I've seen it, not too bad a series. Though I wish they would make a third season and conclude things, it felt a little too open ended. But meh I've seen more un-concluded endings before in a series.

Though personally I didn't like Shinku all too much, her personality annoyed me too much. I much preferred Suisei-seki and her constant insane plans. Though I thought her twin sister was a dude when I watched the opening. I was surprised when they finally gave her a gender definitive pronoun.