alien 9 is amazing. i definitly reccomend to read the manga too if u havent already, it only gets better. i really love hitoshi tomizawas metaphorical stuff in it. another great manga he made is milk closet, it also has a lot of lolis suffering and subliminal imagery that made me cry, i wish that got animated too. the only series that gave me a similar feeling was narutaru, it had a lot of stuff that gave me the same feeling to alien 9, though i still like alien 9 better.