One guy, several girls and a heap of mishaps are the base ingredients to what make a harem however Sekirei does things a little differently. Rather than focusing on being a typical Harem, Ecchi, Rom/Com; here we have a sort of battle royale, with a "gotta catch 'em all" feel to it. But instead if catching cute Pokemon, these trainers gotta catch cute girls, not with a ball but with a kiss. Oh, and occasionally their clothes explode.
The "Sekirei Plan" is a super duper secret project where hot girls & guys of unknown origin have to fight, fight and fight some more. Why? Who knows.
What's the point of it all? Probably for the enjoyment of a deranged multi-billionaire, who spends most of his time ranting and raving atop his ivory tower. And no, that is not a joke.
Down on the street-level, Minato Sahashi is the young man who’s thrown into this startling, unfamiliar situation, where he becomes the Ashikabi (partner) of one of the 108 Poke- Sekirei. A cute girl who goes by the name Musubi, with her augemented abilities and augemented physique. Her goal is simply to fight for her master. Why? I dunno... I guess to be the last one standing and win... Something. The main plot of the story is established by the first 3 chapters, yet it just isn't explained well. It's usually through the multi-billionaire game master’s eccentric monologues, or through some other character imparting some exposition they've been withholding. Honestly a lot of the dialogue just feels unnatural and the battle royale itself feels uninspired and becomes rather convoluted, as it tries to shoehorn in some depth. But inbetween the fights and exposition dumps, Minato is just a guy, going with the flow and trying to make the most out of the situation he's found himself in, which is fairly enjoyable. Especially as he gradually increases his roster.
Which is weird to say, because these aren't animal-like creatures, one sends into battle to slaughter one another. These Sekirei are basically like augemented humans, with a variety of personalities and desires... That one sends into battle to slaughter one another. Although there are meant to be 108 Sekirei, the story spends the bulk of its time focusing on the ones Minato claims and the Sekirei they intereact with. So there's a good 2 or 3 dozen for fans to pic their favourites from and make doujins on. As for Minato himself. He is quite frankly a self-identified useless NEET, who manages to luck out of his stagnant life, somewhat from ident of birth. Nevertheless he is one of those protagonist who attains some character growth as the story progresses but not enough, as he remains weak-willed throughout and one can easily tell this by the demenear he is drawn (usually on his hands and knees).
Well sure Minato is not much to look at but for an ecchi harem manga, featuring a boat-load of cute girls, the mangaka can just unleash their creative juices on the page and carry even a subpar story with their art alone. Which is why, it is with a heavy heart, I must say that those hoping for a bit more creativity would find the artwork for Sekirei rather lacking. Simplistic character designs, with wonky features and exposed-lopsided breasts are just some of the issues I personally had. Let alone the background environments which are all rather basic; lacking a sense of detail and shading, to elevate it to greatness. All in all, it art looks incredibly simplistic and usually the simplicity in the art would make action sequences really easy to follow (take World Trigger for example), but even there the mangaka for Sekirei fails.
Overall Sekirei is a Battle manga, with mediocre battles that one can only follow by reading the attack moves. An Ecchi manga that fails to arouse, due to the lacklustre artwork. But a Harem that holds some interesting character dynamics and relationships. I wish it just had more of those fun character interations and less of the clusterfuck it had towards the end. Sekirei is really the kind of manga I enjoyed many years ago, but re-reading it now (2017), after reading a 100+ superior manga, it makes it very difficult to ignore the flaws.