I like the summary of : "These girls take advantage of their special abilities and fly around the shadow world." I normally don't enjoy non-modern settings, but I may take a gamble and try it out! Is it on anything like Hulu or Netflix?
Also, I would highly recommend watching Kimi No Na Wa if you are short on time but appreciate a good anime. It is a movie, so you don't have to commit to it long-term. :)