I really enjoyed most of it for its charm and intelligence, but it's capable of being time-wasting and/or stupid. It's a fanservice harem show. The genre trips it up. Nonetheless, for the most part it's likeable, sweet and funny.
Our hero is a boy called Koi, who lives in Okinawa. Tropical island paradise. Nice. In episode one, he shows up to his grandfather's funeral and finds a big-boobed alien cat girl (Eris) hanging out with everyone and sharing the food. No one minds. They don't even seem surprised. Folks must be laid-back in Okinawa. Anyway, Eris turns out to be the representative of the Catians, from the planet Catia. (Yes, there are also boo-hiss Dogisians.) All these aliens are female, obviously, although the viewer will soon decide that perky cat ears are sexier than droopy dog ears.
I'm more than happy with everything extraterrestrial in this show. It's been thought through in detail by someone genre-savvy. Every time I spied a potential cliche, the show would avert it by choosing the more intelligent option. I'd purr. It's satisfying. The Catians make contact with Earth's governments, start negotiations for formal approval and in the meantime make Kio's house their embassy. They worry about legality. (In their embassy, of course, Catian law applies rather than Earth's.) They hire employees. They have fierce security protocols for who's allowed to give orders to their spaceships. Late in the day, when their mother ship's in danger of crashing into Earth, we're told about the horrible consequences should this happen... and then about the Catians' safety systems that mean the planet's not in danger after all. The Catians themselves are still in deep trouble, obviously, but the details of how and why get surprisingly complicated.
I also liked the characters. Koi is a Nice Harem Hero, but he's also sensible and immune to Comedic Embarrassment (TM). The latter in particular is a pleasant surprise. Eris finds pornography under his bed and assumes that this is representative of Earth interaction. (Don't worry; this only gives rise to modest misunderstandings, all resolved by people calmly talking to each other.) Anyway, the default response of an anime character to the aforementioned discovery would be shock, denial or some other comedic overreaction. Koi, though, does none of all that, which would in any case have made him look like an idiot because Eris has the hide of an easy-going rhino and never turns a hair at anything. Instead he just explains it all to her.
In fact, Koi's so practical and straightforward that he makes a lie of descriptions of him. Manami sees him as a typical harem hero (wishy-washy, indecisive, etc.), when he's clearly not. Mind you, Manami has issues.
Anyway, Koi and Eris are great together. They're both direct, honest and will tackle tricky situations by discussing them. When terrorists show up in episode two, waving guns around, Eris starts asking intelligent, polite questions to dissect their bullshit.
"Well... sorry to interrupt, but who are you again?"
"We speak for all humanity."
"So, generally speaking, what areas of humanity do you represent?"
"You don't need to know."
"I'm here to analyse the present situation of this planet, so I think I should ask what sort of organisation yours is. So, please tell me."
Even when Eris is throwing herself at Koi because she's on heat (yes, really), she'd already explained the situation to him and so they're calm and level-headed about it. (Nothing happens.)
So we have aliens. They're impeccable, assuming you can live with the idea of Catians and Dogisians. More oddly, it also turns out that, by a unexplained coincidence, almost everyone in Koi's life seems to be a super-skilled government killer or secret agent. His childhood friend Manami Kinjou works for the CIA. The shy movie buff is an assassin for the Japanese Immigration Bureau. (That's a scary anti-immigration policy.) His schoolteacher is the head of a terrorist group, the Beautiful Contact Japan Sect. His uncle is... okay, I think I lost track by this point, but he's something. And there's more.
It's ludicrous, but it's part of the set-up. The show wastes no time and even less shame on clobbering you with it, so you go with the flow. What's more, it's inverting the trope of mega-tech visiting aliens outclassing the local humans to such an extent that the latter might as well not exist. That's not true here. On the contrary, Koi's friends are serious badasses. One of them has mutant powers.
As a result, this show has a knack for startlingly impressive action sequences. They'd be attention-grabbing even in an all-action fighting show, let alone in fluffy harem fanservice.
This show has a ton of things to love. We have killingly funny terrorist organisations, either worshipping Eris or finding her offensive for silly reasons. We have the Nudity Gun, which is one of the best things ever. We have the Catians defending themselves against top-level Earth military hardware with comedy Acme hammers... and it works! We have the best reason ever for establishing official interplanetary contact. (It's at the end of episode two.) We have a sniggering mute dog sidekick called Muttley, even if he's not as good as Dick Dastardly's. We have the Assistaroids, the Catians' lovable robot assistants, who look like cinematic icons (e.g. Chow Yun-Fat) and communicate via handwritten signs. There's so much to enjoy here.
Oh, and each episode's pre-credits sequence is a homage to an English-language TV show, e.g. Star Trek, Mission: Impossible, etc. I lost it when they did Red Dwarf. I think I had to pause and rewind because my brain had been on hold, boggling. What's particularly amazing is how well they make the two shows fit.
So that's the good stuff. The showrunners know their SF, as shown in names like Orsonians. That's one level of genre awareness. More worrying, though, are the harem elements and fanservice.
Good news: the latter I actually liked. Fanservice in anime can often get tiresome or creepy, but here it's fine. It doesn't vandalise the storytelling and I found some of it funny, e.g. the Nudity Gun. The show isn't leering at the characters or pushing them into ugly sexual situations, but instead is being casual and light-hearted. It doesn't snigger. The cast doesn't include a Comedy Pervert. The girls' cup sizes are within the limits of plausibility, rather than being deformed freaks, and the flat-chested Aoi isn't treated as a second-class citizen or given A-cup angst.
I wouldn't be embarrassed to show it to female friends. The DVD/Blu-ray editions have even (praise the Lord) added the nipples that were omitted for TV broadcast. I can't be the only person who finds anime nipple-free breasts to be faintly disturbing.
No, it's the harem genre formula that torpedoes the show.
Some of it's Aoi. Her subplot is theoretically quite good, but it's mishandled. The frustrating thing is that there's a lot of storytelling potential in a girl's unrequited feelings, especially given her conflicted motivations and the fairly complicated relationship she has with Manami. Here, though, it doesn't work. This isn't a romantic show. There's not even an ounce of it. Koi and Eris will presumably be ending up together, but even together they're just good friends. Admittely this is a definition of "just good friends" that occasionally includes Eris being in heat and jumping on top of Koi, but even then he'd just be trying to help her get back in control of herself. Aoi's hollow subplot is thus empty of drama, except paradoxically in her relationship with Manami. It's not going anywhere. It's dead space. You don't care and it's wasting your time.
It's by the numbers, churned out according to the harem formula. The showrunners are following their template off a cliff, although in fairness it's conceivable that it works in the manga or the original light novels. I'm speculating. I haven't read either.
Aoi's merely a good idea done badly, but Manami is a stupidity engine. I've been complimenting this show on its intelligence, but Manami torpedoes all that. It's because she's another harem cliche, in a show that's otherwise raised its game so well that she doesn't fit. She's a good-natured but violent tsundere and Kio's designated clobberer, who'll beat him up if he ever sees her in unfortunate positions. It's never his fault, though. His "crimes" include: (a) walking into his own living room, or (b) running to help after hearing gunfire in a public street. On one occasion, she even starts firing an automatic weapon at him. (That's not a nudity gun, by the way. She's shooting at her friend with real bullets.) For goodness' sake.
Then, during the finale when our heroes really don't have time for it, she starts giving speeches about Koi's love life and other people's feelings. She does this when they're under attack by an alien fleet, for instance. My notes say "FRUSTRATING MORON TIME" and "STOP IT STOP IT". The episode recovers later, with bravery and a satisfying ending, but some will undoubtedly think that the episode had already been wrecked by Manami's idiocy.
And since that's the finale, that might feel as if they've wrecked the show.
That said, I like the relationship between Aoi and Manami. It's complicated and has undercurrents that eventually snap. That's cool.
There's a gentle theme of TV and movies. Characters watch it, the Assistaroids pay homage to it, the pre-credits sequences parody it and the plot includes different kinds of movie-making. (Kio's a member of a filmmaking club who amusingly regard Eris as not alien-looking enough, while episode five has Aoi and Manami getting involved with the camp director of straight-to-video action flicks. This gives us the outrageous bikini boat chase, which is another example of the fanservice being funny.)
There are also some moments where the anime finds genuinely interesting notes to play. Its use of VR in episode six is intriguing, while episode nine and its use of song have been rightly acclaimed.
Geopolitical implausibility: when our heroes visit Russia in episode 11, some NATO battalions just happen to be nearby. They're only three hours away, at "trundling tank" speed. In Russia? Clearly this is an alt-universe Russia, not led by Vladimir "invade Ukraine for getting too close to NATO and the EU" Putin.
The OVA is fluff even by the throwaway standards of bonus OVA episodes, but so shamelessly that I sort of respect it for that. Strip mah-jong? Strip chess? Strip "rock paper scissors"? Mind you, the villain still being alive makes me wonder if it's set during the run of the show, not after it... which in turn means that perhaps a late minor plot development (ears) didn't get reset-buttoned after all.
Even with Aoi's subplot and Manami being too stupid to live, I admire this show. It's a fanservice harem show, yes, but it's 90% clever and genre-aware, e.g. the "toast in mouth" gag. The SF elements are satisfying, the action sequences are spectacular and the characters are very likeable, including Aoi and Manami. Kio is vanilla, but that goes with the "anime harem hero" territory and I was fond of him anyway. The show tries hard to cripple itself, but even so I'd recommend it if you think you can get past that (and the boobs).