I quite enjoyed it. It's harem-ish fanservice with almost nothing new or original, but I thought it managed to tell a halfway decent story of demon-fighters anyway.
The token bloke is bland. (The cast is one part male and all the rest female, of course. No, I tell a lie. There's the Mandatory Boob-Obsessed Pervert Classmate At School.) I was discussing this show with a friend who'd also seen it and he'd forgotten that it had any male characters at all. He's the protagonist! (Technically speaking.) This should be bad. In practice, though, it's good because as usual the girls are much more interesting and we don't want to waste too much brain space on Generic Bloke.
He has a name. Um... ah yes, Shinichirou.
What's more, the show has a decent reason for its harem set-up. The girls aren't just all randomly in love with him. He's apparently an ordinary high school student in a cast of demons, demon-hunters, witches, etc. but he has two or three handy magic powers. (I'm vague on the connection between them, though. Him having all these random powers feels like convenience plotting.) These are:
POWER #1: he can divine your true name if he makes oral contact with you, e.g. a kiss. This alarms people because this is a magical series and knowing someone's true name gives you power over them. If they're a demon, they become your slave.
POWER #2: he can recharge your magical life energy with his own if he makes oral contact with you. (You might have spotted a pattern here.) He's a magical battery. This makes him handy in a fight, even if he can't fight for himself.
POWER #3 (if you'd call this a separate power): he can recharge his own magical energy at super-speed. A good night's rest can bring back as much life-energy as you or I would get from being bedridden for six months. My guess is that this might be connected with his lack of sex drive. This is a teenage boy who doesn't even seem to have considered the possibility of taking advantage when naked women are throwing themselves at him. Is he gay? Dunno. Do I care? Hell, no. I don't know if I'd even technically call him the protagonist, since he's more of a protagonist-shaped hole in the story. He occupies the place where you'd expect a protagonist to be, but he's too much of a passive blob of Noble Nobody traits. Let's talk about the girls!
The main girl is Sakuya Shimazu. You can tell she's the one who's meant to get the boy because she's a violently abusive tsundere who gets embarrassed when she's naked, usually due to clothing damage in battle. (Her rivals all have bigger breasts, no shame and no nudity taboo whatsoever.) Characters like Sakuya have become an anime cliche, but she has intelligent reasons for her viewpoint and I thought the shading between "aggressively hostile" and "visibly human" was quite well done.
Her emotionless cousin and rival, Suseri Shimazu, at first seems like a fanservice opportunity looking for somewhere to happen. She's also openly offering herself to Shinichirou. However her backstory in ep.8 makes you realise how damaged she is. She doesn't even know what food or clothes she likes.
Then there's the cat demon, Tamako. She ends up getting literally enslaved to Shinichirou, but she adjusts to this very comfortably. She's the most fanservice-friendly of the cast, which is saying something, but that's because she's a cat in a human-ish body and doesn't even realise that the others might have a problem with her jumping around naked.
Apparently, in the manga, a sword turns into a fourth harem girl. So we were spared something, at least. Besides, there are several female characters with no designs on Shinichirou at all. The character dynamics aren't actually that exploitative. It's just good old-fashioned sleaze, e.g. multiple accidental kisses, face-in-groin "whoops" moments, rampant nudity for contrived reasons, etc. This is really annoying in the censored TV version, but watchable on the more explicit Blu-rays if you have a thick skin. It's just nipples. Lots of nipples. At least that's better than the creepy no-nipples nudity that the anime industry sees as more family-friendly.
It's worth pointing out that this is an Arms Corporation anime, though. The studio isn't entirely fanservice-focused, e.g. Maoyu, but they've done out-and-out hentai as well as notorious boobfest titles like Queen's Blade, Ikki Tousen, Valkyrie Drive, etc.
The plot's sufficient. It's unmemorable and it doesn't end strongly, but it does the job okay. The girls have enemies, but more importantly this is quite a violent show and the tone feels appropriate to that. Shimazu is capable of being the direct cause of three deaths in a huge fountain of blood. The focus is on the characters, not the storyline. Overall, I'd say this is a modest but perfectly solid effort that would have been better received critically without that focus on sexual content. It has the odd lazy bit, e.g. "get in the right position" is meaningless in ep.4 as far as I can see, since Sakuya can shoot her arrows just as easily either way. That's just a contrivance to give Bland Bloke something to do. However the show's taking itself quite seriously and I thought it was telling its story just fine, apart from the fanservice.