As I predicted, I've ended up watching all of OreShura. As its gone on, I've managed to isolate the one thing that really puts me off harem shows.
Don't get me wrong: there's a lot to hate about harem shows. I can't think of any, off-hand, that have any redeeming features whatsoever, that aren't immediately overruled or offset by the harem cliches.
If it was a straight story of the fake-to-real transition of the relationship between Eita and Masuzu then it would probably be one of my favourite shows. But then they drown it in childhood friends, long-lost classmates and assorted weirdos - all of whom have an equal chance to "win" the hero1. There are so many contrived situations, which the characters fail to react to in any way believably, that any brief moments of real warmth just come across as emotional fanservice to go along with the visual variety.
The main story, which has two anti-romance misanthropes slowly falling for each other as they pretend to be going out (in order to avoid unwanted attention from other people with genuine romantic interest), is actually quite interesting. I'd like to see that show, even if it was still dressed (or undressed) as this cheeky comedy - not every show needs to be Kids on the Slope or Wandering Son. But Eita's very quick to let his guard down with Masuzu and seems to believe her fake girlfriend routine himself even as she's blackmailing him. But because there are three other girls vying for his attention, he has to have equal moments of "will they/won't they" with each of them in case a quarter of the audience rebels.
I know it would be difficult for a romantic comedy to keep up 13 episodes without some source of tension in the relationship (in Kare Kano there are several: Yukino's studying obsession, Arima's inner demons show up a few times, and then there's Hideaki). The easiest way for OreShura would be to keep the (first) childhood friend angle, but I don't think it would be impossible to lose Chiwa and still have some hurdles for the would-be couple to overcome together.
At the end of the day, I guess I just feel like the show's treating me like an idiot - someone who can't stay interested without cheap fanservice and tsundere bullshit at every turn. I know there's a market for this crap, and I'm probably not helping by watching (and talking about) it so much.
But I'm a sucker for stuff with "potential to be great", and the hints that OreShura might be just about to take itself seriously for a second - even though I know in my heart it never will - crop up just often enough, usually right at the end of an episode, that I can't stop myself from coming back the next week.
Thank Christ the season ends this week. I might be able to stay away from the inevitable series 2.
1 The way harem anime fans talk about the story and characters, by the way, is pretty creepy. The terminology used is lifted straight out of visual novels and eroge; they talk about "best girl" and paths and harem endings (I know they're not real people, but this seems disrespectful to the characters) and they're all very detached, which seems oddly opposed to the intended emotional resonance the audience is, I gather, supposed to get from rooting for one girl over another.