I read the manga version many many years ago.....since then I forgot the name of that already, I tried to search without a clue for long. Once in a while, I came across with this anime version and recognized the plot and the characters. Thanks to the awesome Internet (and MyAnimeList), I could finally put my long-time search to an end. This anime version is somehow different than the manga version, and I am not going to include so here. And I want to say that, this Ai City anime kind of makes me like the bad guys more than the good guys, which isa rare case to me.

Despite the fact that Ai City was made in the 1980's, there were some revolutionary sci-fi ideas being added to make this a unique classic.

Lastly, I just want to mention again that, I was able to retrieve the manga name of Ai City, all because of my discovery of this anime version.