Gyakuten Sekai no Denchi Shoujo

Similar plot setup and characters: Denchi Shoujo Rumble Garanndoll involves a victorious Imperial Japan from a parallel timeline invading the Japan of our timeline where Otaku culture thrives. A group of rebels that love all things Otaku, anime, manga, tokusatsu, mecha, idols and games come together to revolt with the hero using a mecha powered by the various girls he encounters, the lead one is a redhead voiced by Ai Fairouz. In Mahou Shoujo Magical Destroyers, an authoritarian government emerges in Japan during the 2008 financial crisis, confiscating all anime/manga related merchandise and putting Otaku into protection zones. A group of revolutionaries led by "Otaku Hero" and magical girls Anarchy (redhead, also voiced by Ai Fairouz) and Blue fight back against the government. read more 

Concept/settings are very similar. Both take place at akiba where otaku fight against goverment that try to eliminate otaku. Both comedy as well 

can't say anything, basically similar, only the difference is one magic and one mecha 

The power of Otaku! Both series are self-ware parodies of anime, particularly the mecha genre, with hilarious over-the-top and energetic characters. Akito Tenkawa partakes in the "civilian falls into cockpit" trope, being reluctant as a pilot as he was severely traumatized by war, only wanting to be a cook, but at the same time he is a huge fan of an old Super Robot series, Gekiganger. He has fellow mecha Otaku Gai Daigoji as a pilot (who is way more enthusiatic about it) and his ditzy love interest/captain Yurika Misumaru is keen on keeping him on her ship as her knight in shining armor. Hosomichi is a host who just wants to make a living in heavily censored Japan. He similarly ends up piloting Shark One out of circumstance and meets its battery girl Akagi Rin, an avid fan of a the superhero/mecha show Zaburn (which Hosomichi liked as a child). The antagonists of Nadesico and Rumble Garanndoll can be compared and contrasted as the Shinkoku Nippon of Rumble Garanndoll revile anime, games, manga, idols etc. heavily censoring them but behave in a very old-fashioned militaristic manner; they are extremists against Otaku. The Jovian Lizards of Nadesico, on the other hand, also hold old-fashioned militaristic views, but that's because they have built their entire culture on Gekiganger; they take being an Otaku to its extreme.  read more 

Both share the same sci fi/mecha tropes. They are also similiar in tone and its characters are inspired by fictional mecha shows within the anime