It's a number of things that don't gel particularly well. These are:
(a) a harem anime with light-hearted comedy,
(b) an exploitative boobfest in which almost every female character has breasts like wrecking balls and often gets naked,
(c) a surprisingly brutal thriller about an alien superhero deathmatch contest in which losers get killed.
I mostly enjoyed it, but it doesn't quite square that circle and I'd call it at best a second division title. Oh, it's quite good. Parts of it are excellent. However I can't imagine it being anyone's favourite, instead perhaps sitting at the level of "better than I'd expected, considering".
The story involves superpowered aliens called Sekirei, who came to Earth as embryos or fertilised eggs when their spaceship crashed. Now it's the year 2020 and they're 21 years old. They're mostly female and outrageously buxom. So far, so exploitative. The Pokemon harem element involves Ashikabe, which is a word for humans with special genes that let them form bonds with one or more Sekirei. (The more Sekirei you can collect, the more superpowers they'll have and the more formidable they'll be as a team.)
So far this probably sounds like otaku wish-fulfilment, but there's also the Game, aka. the Sekirei Plan. That's a deathmatch run by the MBI Corporation for the amusement of its chairman, Hiroto Minaka. It takes a while for the full brutal truth to come out, but the Sekirei are expected to fight each other until only one's left alive. Most of them seem to accept this (why?), but if you try to run away, MBI will come after you with their private army, battleships, tanks, missiles and personal Sekirei.
That's this show's strongest and most distinctive element. The deathmatch is a brutal, bloody Sword of Damocles hanging over everyone's heads, even if it doesn't get going properly within the show itself. They only animated the first half of the original manga, you see, with the Battle Royale not starting in earnest until the chapters that would have been the anime's never-produced seasons three and four. That doesn't really matter, though. There's still more than enough to prove that this is an ugly world where even superpowers won't necessarily keep you alive and innocents are liable to get cut down in cold blood. This isn't a fighting anime. It has fights, certainly, but not enough to please fight anime fans. This show's battles aren't exciting escapism, you see, but instead are dangerous. Combat brings death and massive property destruction. Our heroes aren't motivated by any desire to win. Season one's finale is about trying to help people escape the MBI's reach, then season two's finale is about trying to beat the bad guys to win medical help for a sick girl.
At times, this is excellent. The bad guys are scary enough that you're genuinely afraid for our heroes in the season finales. Meanwhile the assassinations and martial law are disturbing, while some characters have an emotional stake in the bloodshed, either because they're trying to escape or because they're being forced to work as an assassin for the villains for the sake of their Ashikabe. The tragedy of Uzume is simple but memorable. She's a good person, but she's going to end up being ordered to kill her friends and she's not going to hesitate. She just really, really loves her terminally ill Ashikabe, you see. That story provides the show's strongest material.
All this I like. The danger is real, the destruction at the end of season two is amazing and the series is exploring the grey areas between hero and villain. Uzume is a good person, but doing bad things, while one of our hero Minato's Sekirei looks and sounds like a baddie.
However there's also the harem formula.
The weird thing is that this is also fairly good. It's fun and entertaining, while I liked the occasional angle of drawing attention to the disturbing side of the "willing doormat" nature of a lot of harem anime. Sekirei will obey their Ashikabe like slaves, even the guy's a boor, abusive, violent, an embarrassing social disaster or sexually exploitative.
Nonetheless I also don't think it's entirely successful. There's a clash. Harem anime tends to be a bubblegum genre, but this series is a brutal near-future thriller, no matter how silly and fluffy it might often be pretending to be. I liked the cast, but they're not everything they could have been. Worst is Musubi, who's an empty shell of a character. She has no quirks, no intelligence and no inner life beyond "empty-headed and cheerful". Theoretically she's the main girl, but look at how quickly the show stops bothering with even the token, formulaic twitches of characterisation she had at the beginning. (She eats a lot, for instance, but how often do we see that beyond the first episode or two?)
I also didn't like the landlady. The show wants her to be scary in a soft-spoken way, but it does this by drawing a demon face behind her as she's talking... instead of, you know, by doing anything that might make us even the tiniest bit scared of her. That demon face appears all the time. I was getting annoyed with it almost immediately.
Matsu and Kazehana are okay, but no more.
Three characters I actually liked, though. Minato, the male hero, is surprisingly good. He's as noble and kind-hearted as is traditional in harem anime protagonists (which I like), but he also has a spine. Then there's the angry, hostile Tsukiumi, who gradually thaws out while remaining a fiercely old-fashioned and honourable warrior. (She's also amusingly competitive and will hold silly contests with Musubi, which she takes deadly seriously.)
My favourite, though, is Kuu, who's adorable. She's just a little girl, you see. She loves Minato as much as the other Sekirei and she's as possessive and protective as any of them, but in a childlike way. It never stops being funny to see Kuu in direct competition with mega-bosomed warrior queens. She made me care in episode three after I'd been frothing rage and hatred at episodes one and two. She's great both in comedy fluff scenes (making the show more palatable by being an antidote to fanservice) and in battle scenes (having plant-controlling superpowers and the ability to throw tanks around like toys).
Finally there's the fanservice, which is enough to choke you. It gets less cringeworthy as the show goes on, but even so this is a show with a deep interest in exploiting the female form. If a conversation can take place in the bathhouse, it will. Enemy attacks tend to tear your clothes in the nipple region. Shirts are made of tissue paper and no one wears a bra underneath. There are also lots of panty shots.
Firstly, this is mildly unpleasant to look at. Almost every pair of boobs is exactly the same, faintly uncomfortable-looking, size. (There's dialogue about Kazehana being more buxom than the others, but in practice she looks indistinguishable from them.) The butt shots are bizarrely ugly.
Secondly, and more bizarrely, it's not even sexy. You end up hardly noticing it. You see, everyone's so matter-of-fact about the nudity that it carries no sexual charge at all. It's like a nudist colony. Besides, they're tending to wear skin-tight tops that only cover strategic portions of the available acreage, so it makes little difference to lose those last few scraps of cloth. The show's desperately shoving all this flesh at the camera, but the characters aren't treating it as anything special and so you don't either.
The show's chaste! You could almost call it innocent. Thus, despite all the nudity, I personally find the show far less offensive than, say, Haiyore Nyaruko. Harem shows can be filthy, but no one here is trying to shag anyone. Admittedly one or two are capable of innuendo and there's an Ashikabe who must surely be taking sexual advantage of his Sekirei (two sisters), but that's as far as it goes. That's partly thanks to the "scary" landlady and her hatred of dodgy behaviour, for which I am indeed profoundly grateful.
1. There's bad art in season 1 episode 11. The action scenes are awesome, so presumably the producers scrimped on the artists after splashing out on the animation.
2. The seasons end apocalyptically enough that I didn't mind only getting halfway through the manga storyline. The anime successfully stands alone, although I'm sure it helped that I had season two waiting when I finished season one. It would have been nice to get seasons three and four, but what the heck. However this cut-off plotting causes the odd quirk, though, e.g. our hero being unaware throughout that his sister Yukari's become an Ashikabe. It's not a serious problem, mind you. One has faith that that plot thread must be going somewhere. We just never reach that point during the anime. Yukari and her Sekirei spend the entire show wandering around in a plot bubble, never interacting with the main characters.
3. I don't quite buy Minato turning down the chance to escape at the end of season one.
4. The "difficult test" in season 2 episode 4 is supposedly in English, I think, but it's clearly just a non-English speaker filling the page with random characters.
I enjoyed this one. It's not brilliant, but it can be very funny and it has powerful material like the tragedy of Uzume's lesbian love with her Ashikabe. It also has quite a complicated mix of ingredients, which has led it to be underestimated by people who complain about the relative lack of fight scenes (it's not a fight anime) or the bad romance (it's not a romance). Meanwhile the plot's strong and fast-moving. If you ask me, the move to half-length seasons was the anime industry's second most important development of the last few decades, eliminating a lot of padding. (The most important was of course computer-assisted animation.)
The harem stuff isn't special and the fanservice can get tiresome, but I like the show's combination of a dark world and good, kind people learning to care for each other. Far more palatable than you'd expect.