In short, Seirei Tsukai no Blade Dance takes place in a fantasy world where magicians called Elementalers (or Elementalists if you prefer) form sacred contacts with elemental spirits in order to be allowed to wield their powers. However this privilege is only given to pure maidens of noble families who undergo training in order to become spirit contractors. This means that there are no male Elementalers... or at least there shouldn't be but *as it happens*, there is one exception to that, namely the story's protagonist Kazehaya Kamito. Consequently he's transferred to the rich girls' classy school as the only man in an ocean of girls. Sounds cliché and overused as hell I know, but I think it utilizes that premise better than most other such cases out there.
Now undoubtedly the most important part of a harem series is the characters themselves, as if they're not likable then it will suck no matter what, so here's a rough draft of the most important ones:
Name: Kazehaya Kamito
Role: Protagonist
Description: Good natured, dark history, strong fighter
Comment: Not a pervert, not a wimp, not dense. Actually a competent harem protag for once
Name: Terminus Est
Role: Contracted spirit, bEst girl
Colour: White
Description: Ancient legendary sword spirit, expressionless, snarky
Comment: One of the most nosebleed-inducing characters in existence, total moe overdose and perhaps the main reason to watch this series. Don't you dare drop this anime before she makes her first appearance (episode 3)
Name: Restia Ashdoll
Role: Former contracted spirit
Colour: Black
Description: Antagonist(ish), motives surrounded in mystery
Comment: Cute yet seductive character design, hard to figure out for sure what she's thinking or what her personal goals are most of the time
Name: Claire Rouge
Role: Tsundere Ojou-sama #1, emphasis on the tsun
Colour: Red
Description: 95% tsun, 5% dere, Kamito's self-proclaimed "Master"
Comment: Imagine Louise de la Vallière except without Kugimiya Rie and you won't be too far off the mark. Also a closet pervert though
Name: Rinslet Laurenfrost
Role: Tsundere Ojou-sama #2, emphasis on the Ojou
Colour: Yellow
Description: 50% tsun, 50% dere, extreme rich-girl aura, Claire's childhood friend
Comment: Without a doubt one of the most strikingly Ojou-esque characters out there
Name: Ellis Fahrengart
Role: Tsundere Ojou-sama #3, emphasis on the... creative ways of insulting people
Colour: Blue
Description: 33% tsun, 66% dere, captain of the Sylphid Knights
Comment: Strong sense of justice and a quite straightforward personality, but on the inside she really only wants to be treated like a girl
Name: Fianna Ray Ordesia
Role: Perverted Ojou-sama
Colour: Purple
Description: Playful and teasing personality, frighteningly bad at cooking
Comment: Aggressively seeks to seduce Kamito for her own reasons. She's good at teasing people but not so much at being teased herself. Also somewhat naïve
Short version would be that some characters are more likable than others, but there's bound to be at least *someone* everyone would like from the cast. Est is by far the most popular but Restia and Ellis have some sizable fanbases as well.
As far as the production value goes, the art style looks mostly like how I imagined it would and is quite pleasing for the eyes overall. The animation quality however is uneven at best. For panoramic sceneries and close-up character shots everything looks fine, but every so often during more distant shots the characters' faces will look completely distorted and just plain weird. It really feels like they skimped on the budget in that area and sadly it drags down the overall impression of the visuals quite a lot as it'll constantly nag you in the back of your mind.
The soundtrack however, the only aspect I had absolutely no expectations on whatsoever coming into this as a LN reader, sure as hell was the real surprise of this show. The OST is just soooooo catchy, I was so impressed with it and it really has its own feel to it. It's not particularly J-pop-esque, but rather gave me some East European or tribal vibes... I think "wild" might be a good word to describe it. Note that I'm not just talking about the OP (though this one is a bit more "normal" than the others) and the ED with this, but the soundtrack as a whole including the CD-only tracks (like Shukusai no Elementalia for example) that aren't in the anime itself are also fantastic and I'd recommend you to run to your nearest YouTube and check them out if you haven't. Also one does not simply mess with a group name as legit as Ni-Sokkususu (pronounced Knee Sockss) >.>
Moving on, overall this is definitely not a show that would ever be labelled as "deep" or "intelligent" or "artistic" etcetera, but that's not what an ecchi harem show needs anyway. What it needs is cute girls and mindless fun, and as far as that part goes at least there's not much to complain about. Some people might get annoyed at Claire but she's only one among many, and there's bound to be at least someone that can carry the show for every viewer specifically. In the end, anime is simply entertainment media and for that purpose alone, Blade Dance does its job. That's all there is to it really.
However as a final note, as someone who's read the novels I really want to get this message across: since no second season has yet been announced despite the anime being finished airing, combined with the fact that (to my knowledge) it didn't have the best BD sales in Japan, it’s worryingly likely that no more content will ever be adapted for this series. If that really does seem to be the case however, then I really recommend you to at least try out the LNs instead. I'm not going to be one of those hypocrites who keep yelling stuff like "the source material is so much better, don't judge it by this anime" etcetera, because that is definitely not the case. In fact I think this is a quite respectable adaptation as a whole; not perfect but good enough. Rather it's simply that the story improves immensely pretty much from the very moment at which the anime ends, and thus judging the full story merely from what these twelve episodes cover alone will give a quite unfair image for the series as a whole. This is essentially just the prologue. The main arc of the novels begins literally the second the last episode of the anime ends.
Though if you're not quite that hardcore and simply want to watch a show casually for plain fun, then this adaptation on its own still does a good job at doing just that, and arguably that's really all you ever need to ask for when it comes to anime.
