There's a horde of stock alien invaders rampaging about in the city. There's a pack of (more or less) cool girls using superpowers, throwing about deadly cell phones & easily crushing those invaders like small bugs. Six episodes of this ahead. Is that all? Well, the short answer is: No. Seeing the genre-eviscerating Madoka★Magica shake the mahou shoujo fandom today makes me wonder even more as to why GK 21, being nine years older and attempting basically the same thing, went barely noticed. Perhaps because no one had expected that a follow-up to a light-hearted shounen/action/adventure/harem series would be a gloomy mahou shoujo deconstruction. Yet it'sexactly this. Enjoy.

[Story]
So, there are Invaders. And there are Gate Keepers. They do kick Invaders' asses using their cool superpowers and pavement-melting mobile phones. So simple… Wait, but why someone who possesses a superpower would need some extra gadgets?.. Pardon, these superpowers _what_?.. Sorry, _how many_ Gate Keepers?!.. And those Invaders are… WHAT??! Oh sh**.

The first thing that strikes in GK 21 is the perfectly undefinable genre and tone. The ‘mood pendulum’ swings violently between horror and parody, the most cruel and disgusting scenes getting exaggerated to the point of ridiculous, pathetically bombastic action sequences being run over by dramatic introspections, gags and puns thrown in every now and then… However, the more facts about the setting are revealed, the less room for humour remains. This is a dark and serious genre deconstruction. Accept it and welcome the Apocalypse.

As for the series' connection with its prequel… Are there any references to GK TV? Yes. Does one need to watch GK TV to enjoy GK 21? No. GK 21 is good enough as a standalone work, one can understand what's going on without knowing any facts from the prequel.

[Animation]
Gonzo did a great job. The series abounds in computer-generated imagery, yet it doesn't seem too ‘artificial’. The dark atmosphere to fit the plot is skillfully created by subdued colors and weird camera angles. And there are quite a few showy battle scenes. As for character design, it's quite typical for Gonzo. Some do like their style (me too), some don't (well, tastes differ).

[Sound]
Sound effects are really well thought-out and performed. Plane jets and car engines, big city noises and eerie distant sounds in abandoned streets — everything sounds very realistic. Background music, though hardly being something very special, fits the action quite well. The neo-classical opening song is fascinating, the upbeat ending theme is also not bad. As for voice acting, the whole cast did a good job, but Mamiko Noto (Ghost Girl) is the true star of the show, so believable as if being a crazy ghost were her full-time occupation.

[Character]
In the beginning, Gate Keepers look like a bunch of rather typical characters. Given the series' length and number of fighting scenes, one could assume that they would not change till the end. And that would be a mistake. Each of the Gate Keepers gets her share of character development, and relationship between the two main protagonists, Ayane and Miu, changes dramatically through the series. And on the other side there's Ghost Girl, the most convincing mad villain. So much human, her feelings quite understandable — and still totally mad and dangerous.

[Enjoyment]
I liked GK 21 the moment I've seen the trailer for the first time, and I still enjoy rewatching it years after. This short series is definitely worth giving it a try.

Just one remark: use official subtitles, as fansubbers often tend to turn GK 21 into a total mess. And even with decent subs, google ‘Manyoshu’. Ancient Japanese poetry is important to the story, make sure that it makes sense.