Don't bother watching this one. It's neither funny nor serious. "Light-hearted" is the word, I think. It doesn't grow a storyline until over halfway through and even then I can't say I really cared. It's just a bit of a mess.
It's loosely related to Masamune Shirow's Ghost in the Shell franchise, by the way. The manga is based on some unused Shirow concepts and the world is very Ghost in the Shelly. The main characters are full-body cyborgs, there's lots of cyberspace and robot tank things, etc. The franchises are similar in having uninvolving storytelling that takes a long time to go nowhere, but what's different is the tone. Think of this series as silly anime girls in what's otherwise a fairly straight cyberpunk universe.
The main characters are Nene and Clarion, who call themselves human but have completely mechanical bodies and are often mistaken for robots. Nene is a bubbly, enthusiastic girl who really likes Clarion and wants world peace. Clarion is an emotionless combat robot who doesn't like you touching her cat ears. Half of the show is just random episodes of them doing stuff that doesn't matter. I watched it, but it's the kind of thing that'll make your eyelids heavy if you're watching it late at night.
There's a villain who appears halfway through, but only gets a cameo scene per episode almost until the end. He's a non-villain, basically. He almost never does anything. However there are also some useless comedy villains who do actually do villain stuff, but always fail in silly ways and are about as threatening as a small cage of hamsters. (They're the long-suffering employees of Uzal Delilah, who made them dress up in playboy bunny outfits, swimsuits, etc.) I think being silly with the concept of "villains" is a thing with this series. See the punks in ep.7, for instance, who give our super-tough heroines trouble and should theoretically be fairly scary... and yet they look like the kind of throwaway token punks you'd expect to last about five seconds in a scene where they act big until the hero's chihuahua starts barking.
Ep.8 actually hurts Nene and Clarion. It takes a lot to come close to destroying a superpowered anime robot girl, but you can do it if you set a department store on fire. After that, Clarion takes a surprising job from Nene's silly aunt Takumi, while Nene starts fretting that Clarion might be getting bored of her. Even that's not great, but at least it's a story with threat and emotional impact for our heroines.
Then there's the sexual content, which is technically non-explicit (since they're all Barbie dolls) and yet is still something you might not want to be seen watching. Nene and Clarion can open Pandora's Box. Clarion lifts her dress, showing her knickers. Nene will then put her hand up Clarion's skirt and stick her fingers inside Clarion's crotch, to which either girl might have a mildly orgasmic reaction. This is how robots upgrade their software in this universe. Uh-huh. Ep.10 then somehow makes Nene's lesbian feelings more explicit than they had been already. Oh, and there's also BUER (resembling a demon of the same name from a 16th century grimoire), who has a fifth leg that grows from his crotch. He can stick it in sockets. Admittedly this fits what's claimed of the 16th century original, but he's still yet another cyber-being in this universe who plugs in with his groin.
It's not a bad series. There's not enough there for me to call it bad. I just don't think there's any point in it. It just feels as if someone wound up the anime-atron and left it running. It's a fun show with likeable characters, but it gives me the impression that its creators' ambitions began and ended with "have a laugh". Even after growing a storyline in the second half, its penultimate episode can contain scenes like the following. Nene and Clarion are technically in mid-combat, but then impatient big bad villain Ian Kurtz lets them have a three-minute dialogue scene of reconciliation and expressing their inner feelings. They lie on the floor, embrace and activate their lesbian crotch superweapon. The fight then resumes. (Kurtz's robot loses.)
It's nice. It has a few funny bits, e.g. Buer in ep.12. I prefer it to the Ghost in the Shell TV series. However I'm slightly puzzled that most of its episodes exist and it would be only a little bit harsh to suggest that a plot summary would say "treading water". It's colourful and happy, but it'll make your brain go to sleep.