It's a generic anime. That's all. Don't believe anyone using the words "naughty", "romantic" and "comedy", because those would all be lies. It's not very funny, it's not sexy and it doesn't have the guts to take its pseudo-romance anywhere. It's a bit like a magical girlfriend show and a bit like a harem show, without being either. Its premise is mildly interesting, but the show ditches everything that's not blandly generic as soon as possible.
THE START OF THE SERIES
Tsukimura Mayu is an androphobic succubus who needs help getting over her fear of men. When her powers overload, all men in sight turn into zombies. Spot the unfortunate feedback loop. Oh, and any man who kisses her will have his life force sucked out and will probably die. That said, though, she's also a timid, thoroughly nice girl with no ego and very little self-awareness. (And big boobs.)
Ninomiya Shungo is a schoolboy who can knock out bears with one punch and whose older sister (Ryouko) likes machine-gunning baddies in warzones. (The opening of ep.1 is so absurd that I could only laugh and raise a glass to the show's defiance of reality.) He's also a nice chap who'd never take advantage of a girl. His relationship with Mayu will be warm and supportive, despite Ryouko's filthy-minded meddling.
Houjou Reika is the haughty, tsundere heir to an international conglomerate. She becomes Ninomiya's maid and occasionally gets groped by Ryouko.
GIVE IT A FEW EPISODES, THOUGH, AND...
Remember those man-hypnotising powers? Quietly forgotten. There are times when they'd have been invaluable, but no.
Other characters also turn out to have been secretly succubi (or incubi). I think the final total was five. That's half the main cast. Shungo and Ryouko are human, as are some of their classmates, but you wouldn't have been surprised to learn that Shungo had been an incubus all along, but he'd forgotten about it. It's that kind of show. (That retcon would have let him kiss succubi without dying, allowing a traditional conclusion to the romantic comedy.)
How does succubus biology work, anyway? They eat and sleep normally. They don't seem to need to drain life force... until the final episode, when we learn that they did have to after all and that Mayu might be dying because she hasn't been draining Shungo. (How did she survive to her current age, then?) Oh, and succubus powers still work when the succubus and her victim are five years old. They're kiss-based. Yes, just kissing.
It's a fanservice show that isn't. Mayu is a succubus with big boobs whose "training" involves acting out naughty scenarios with Shungo... and yet the show's tame. The main reason not to show it to children would be that it's bland and silly. It's not sexy. The nearest it gets is some naked aprons in ep.8 and a couple of moments where nipples are almost, faintly, sort of visible through something. Mayu is supposedly bustier than Houjou, yet they're generally drawn the same. The art style is also anti-sexy, with those mildly insect-like faces we used to get in the early 2000s.
For a while, I was indulgent towards the show. Mayu and Shungo were nice, while the show's silliness had been written in letters of fire in ep.1. Silliness is the point. They've already given fair warning of that. It was around the halfway point when I started asking questions like, "Couldn't Mayu have used her succubus powers on those soldiers?" The show descends into angst about boob size. After that, ep.8 and ep.9 both had me fast-forwarding. Ep.8 has Shungo being ordered to make some ramen for Ryouko, which is taken to absurdities I found unwatchable. Shungo visits farms to find the perfect pork and goes out on a fishing boat to catch the perfect fish. Oi. Piss off. Ryouko said she was hungry. After that, ep.9 has the anime cliche of schoolboys trying to invade the girls' hot springs and dormitories. That's annoying even when it happens in shows I like.
There's just not much here, really. There was the potential for originality in the premise, but the show backpedals away from that as fast as it can. You know you're in trouble when you're watching a succubus anime that's doing less with the idea than Rosario + Vampire. Hell, even Astarotte's Toy is better than this. Inevitably, there are forgotten childhood memories and promises. Of course. The show tries to get serious and dramatic in the last couple of episodes, but this doesn't work because it's spent so long being silly and ignoring its own premise. It's not even saucy. If you're looking for boobs, go elsewhere.
Mayu is endearing, though. I can't deny that, although I'd have been happier had the show dared to resolve its romantic triangle at the end. It's harmless. I'd watch it a dozen times before I rewatched Rosario + Vampire.