In principle, I quite like this show. It's about superhero teenagers who get their powers from being horny, but never really do anything naughty. Their clothes disintegrate in every super-fight and the show makes a big deal about H-energy, with a ton of nudity and Blu-ray nipples... but these teenagers wouldn't even have a grope unless they'd been brainwashed by baddies or something. Oh, and the title comes from someone noticing that "H" (for hentai, pronounced "ecchi" and meaning "sexy rude things") plus "ERO" (short for you-know-what) equals "HERO".
Kirara Hoshino is a tsundere with a man-hating reputation, but she used to be outgoing and her current personality is a reaction to her own confused emotions and her embarrassment about them. Retto Enjou is her childhood friend and they're obviously going to end up as a couple, so he's not interested in anyone else. Momoka, Sora and Maihime are their teammates.
Nothing wrong with any of that. I don't mind nudity. It's an oddly tame approach to the concept of sex-fuelled superheroes, but at least it's less offensive than Daimidaler the Sound Robot and less vulgar than Shimoneta. (Both of those shows are far, far better than this, mind you.) The problem is that it's not very good. Nothing in the premise doomed it to turn out that way. It could have been fine, but it isn't. Firstly, it's a harem show. This turns out to be a crippling blow, taking a show I quite liked (eps.1-6) and wrecking it with an overload of girls when the Tokyo Branch show up. They depart again after a few episodes, but by then the damage has been done. I'd been interested in the Hoshino-Enjou story. I was actively hostile to shitty scenes of girls behaving unconvincingly for the sake of the audience's fantasies.
Then, we have the show's problem with new characters. They're often not that bad once they're established, but their introductory episodes tend to be disappointing or rubbish. Ep.5 mishandles Chacha. Her sad backstory has very little emotional weight for the audience. In principle, this is a strong storyline. Rescue the princess! In practice, though, it's meh.
The Tokyo girls are annoying in ep.7, even though the idea of a rival for Hoshino is quite good.
Ep.12 is particularly lumpen. Perfectly reasonable script beats that just flop on screen. Chacha's "am I still useful" could have been a valid worry for the character, but the actress doesn't believe in it and the episode's not trying to explore Chacha's viewpoint at all. The beat just feels like a feed line for Enjou to tell her things she already knew. Ironically, she really is about to be heroic and put herself at risk... but the episode is half-hearted in setting this up.
Shortly afterwards, the "Chacha's betrayed us" line has the same problem. Worst of all, though, is when the baddie (voiced by Kikuko Inoue) mind-controls Hoshino to make her attack Enjou sexually. You see, the show's been setting up a question of which Hoshino Enjou really likes. The tsundere she is now, or the uninhibited girl she used to be? Enjou takes this opportunity to say that he's not aroused by mind-controlled Hoshino because he's turned on by her tsundere side... but what he doesn't mention is the small matter of a girl being forced into sex against her will. Not being tsundere = no no. Rape = no problem, it seems.
You can see the intention. Theoretically, that's a huge character beat for Hoshino. Unfortunately, the script and production are too clumsy to hit their target.
There are good kink ideas. Hoshino regressing to childhood in ep.6 becomes interesting when you realise that she's reverted to her pre-tsundere personality. (What's more, Young Hoshino hangs around afterwards as a permanent hallucination that only Hoshino can see. They keep having conversations.) In ep.11, Enjou's penis turns into a weasel and runs away. Ep.14 (the second OVA) has a nude school. Wow. That's memorable imagery, even if the episode's just the usual rubbish.
I don't hate this show, but I often lost patience with it. It's a clunky bleah that has some good ideas and character points, but ultimately isn't interested in going anything with them. There's some character progress for Hoshino, but not much ultimately changes for her and the rest of the cast are dramatically static and/or underused. (Especially Momoka, Sora and Maihime.) The show's goal is simply to be paradoxically tame harem sleaze and an excuse to animate nipples.
There are bits I liked. Sora's mini-story in ep.13 with Enjou's sister is okay, for instance. Overall, though, the show's too much of a blancmange to achieve anything. Six months later, you might not even remember that you'd watched it.