Usual disclaimer - there may be a minor spoiler or two in this review, but I will avoid spoiling anything significant. I'm also assuming that readers are familiar with at least the basic synopsis of the series (I don't like wasting words re-hashing basic plot).
Sekirei is an interesting case for me, because it's one of the very few series that I had read the manga going in. A friend had recommended it to me, and I whipped through it online in a couple of days, as I enjoyed it so much. I felt that the manga hit all the right action beats, had more than enough touching scenes, and mixed in the fanservice/humour stuff at just the right moments to help break up the seriousness. I would recommend the manga to anyone, as long as a few sketched boobies doesn't offend them.
So I was a little dismayed when I picked up the blu-ray box and saw the packaging - which literally says, in big bold letters, "Boobies for the win!" It was pretty obvious how both the Japanese studio, and Funimation, had decided to market this anime (which isn't a huge surprise, as they market many series that way, but I was hoping that Sekirei would be treated with a little more care).
But in the end, this is a review of the anime, so I will try to treat it as such.
STORY - 8/10
Sekirei suffers mostly from a bit of an identity crisis. Is it an ecchi harem comedy? Or is it a serious story about a young man thrust into an unfair position and trying to make the best of it? The manga handles this balance very well, but the anime puts a little more emphasis on the harem part, and that's likely to turn off some viewers.
Scenes that provide background to the Sekirei Plan, and the last 3 or 4 episodes, dealing with the big escape plan, provide some very solid plot that far exceeds anything in your standard harem comedy. The story also introdcues some very weighty ideas, though most of them are left undeveloped through the end of the first season. The biggest of those themes being that the gist of the Sekirei Plan is that only one Sekirei can be left standing at the end. And given that by the end of the series, Minato has emerged 4 Sekirei, it's not hard to do the math. Your standard ecchi harem series don't deal with the prospect that the male lead's harem members will have to eventually kill each other off, and once you've grown to attached in even the slightest bit to any of these characters, it's a difficult thought to process. I guess the hope is that Minato will find some way to thwart the Sekirei Plan and MBI, but if he loses a Sekrei or two along the way, it will prove to be fairly devastating.
The story elements that are hidden behind the fanservice are very strong (and the harem scenes often do help develop some level of attachment to the various characters), but still undeveloped. If the producers had given them a little more attention, or if they had handled the balance between serious and fanservice a bit more deftly, I would have given this a 9. As it is, if you enjoy ecchi at all, you'll likely find both aspects of the story's dual personality worthwhile.
ANIMATION - 7/10
By far my biggest frustration/disappointment with the series is the choice to constantly replace the characters with silly chibi-looking things during moments of emotion. This phenomenon is present a little in the manga also, but it looks much more jarring in an animated production than it does in a single small frame on the page. It really seems like a bit of a cop-out, and it's a disservice to the more serious side of the story to not have the characters confront emotions in certain situations, instead opting for a few laughs (I guess?) with the chibi crap - does anyone actually find that funny, or is that just a Japanese cultural thing that I'm missing?
There are also a few scattered moments, though it's difficult to miss them, where the character animation just looks odd - like the artist was simply unable to draw them properly from a certain angle. It distracts from what's going on on the screen, but luckily it doesn't happen too often.
Apart from that, Sekirei is a beautiful-looking show. The Sekirei powers are often quite visually stunning (particularly Tsukiumi's water-based attacks). I should mention that I tend to watch a lot of these series on a 120" projection screen, and if a show looks good when blown up to that size, then I consider the animation to be very strong.
SOUND - 9/10
I have yet to encounter a Funimation English dub that I didn't find to be outstanding. Say what you want about the company, but they put the effort into their presentation, especially when it comes to voice acting. Strong voice acting adds so much to the character development that I can't stress enough how important I consider it to be.
I'm normally not too keen on the opening and closing songs that seem to exist for just about every anime. But Sekrei's themes seemed appropriately touching (even though I can't understand the words being sung) to the more serious side of the show. The in-show score was solid, though not outstanding.
CHARACTERS - 8/10
As someone who read the manga first, it's difficult to approach the characters with a completely blank slate - I've already formed connections with them before ever viewing the first episode.
On the surface, all of the characters have the appearance of just filling some standard archetype - Musubi is the bubbly airhead, Tskuimi is the tsundere, Kusano is the loli, Minato is the flavourless male lead, etc. But I think that all of these characters bring more to the table than just filling some cliche role. The first season of Sekirei doesn't get too far into the development, but it's there - particularly towards the end.
Minato shows a wider range of emotions than is generally custom in harem males, because the more serious side of the story allows him to explore different aspects of his personality than just blandly sitting around being oblivious to the affections of a bunch of hot women. He actively makes decisions and those decisions impact how the other characters view and react to him. I found him to be a much more interesting lead than I've seen a lot of other reviews give him credit for.
As a viewer, you have to be paying attention to the show to really see the depth that several of the Sekirei show. I fear that most people will just gloss over the series due to its strong ecchi feel, and will miss what's lying just under the surface. I feel that Tsukiumi and Musubi, in particular, show real growth and genuine emotion. Matsu is probably the worst-used character, as it is a bit difficult to do something with a woman who never leaves her creepy screen-filled room.
The secondary characters in this show are often well-done. Mia, Uzume, Seo, and the crazy Minaka are all well-utilized minor characters, each of them bringing something to the table. Minaka can seem a little over-the-top most of the time, but he really is a delicious villian - he's the one forcing the Sekirei to fight one another, after all. The problem is that there might be a few too many minor characters - given that there are 108 Sekirei, and nearly that many Ashikabi, even if they introduced only a fraction of that number, it's still a somewhat overwhelming amount of minor characters running around.
OVERALL - 8.5/10
Sekirei is the type of show that I think a lot of people who consider themselves to be serious consumers of anime as an art form will probably shun, just on its face. A lot of people won't bother to give this series more than a cursory glance, see the ample fanservice, and turn away. And such is the life of an ecchi series, I suppose. But I find it a little unfortunate that the series won't get as much positive attention as it deserves because the producers felt that highlighting the fanservice over the story would earn them a few extra bucks.
Sekirei is a show that attempts to be more than your standard ecchi. And while the manga does a better job of it than the anime does, it is possible to find a balance between ecchi and a good story and good characters. I found that the characters resonated with me after I turned it off, and that I was genuinely affected by several of the emotional moments towards the end of the series.
If you're a person who appreciates both ecchi and a good story, then you'll love Sekirei.