If the premise alone does not make you gag then you have passed the single biggest barrier to appreciating this 12 episode series from the Winter 2014 season. Other negative things that could be said about the series – and there are plenty – probably will not matter. The concept has been twisted and tweaked to cater to a very certain subsection of otaku and does not seem to give a damn that it has no appeal beyond that. But hyper-tailored fare is not automatically bad, and some moments in the series do show flashes of much greater potential. Sadly, getting to that potential requires wading through a whole lot of messy dreck and picking the choice content out of the muck.

The core concept - new opposite-gender teen stepsiblings are left living on their own when the parents exit the picture – is a hentai staple, but it is an awkward enough situation that it has all sorts of potential for being explored seriously. Indeed, Mitsuki and Yuuya are set up appropriately for the scenario to play out that way, as neither has any clear romantic interest in the other and both are responding in believable ways to their situation; Yuuya clearly wants to make a good impression and be a responsible older brother, while Mitsuki has a difficult time accepting that she has a male presence in her life and doesn't know how to react. But the series has no intention of being so high-minded. Since the characters do not have any inherent romantic interest, some has to be forced. That is where Hiyori and the magical chastity belt come in, and that is where the series goes all kinds of wrong.

Looked at a certain way, fan service-oriented anime titles (and even some that aren't) often are openly exploitative of their female characters, but usually this does not go much beyond what might be seen in the raunchier live-action American titles. Recently crosses the line from mere exploitation into open abuse, because no lesser description satisfies what the series does to Mitsuki. Two early episodes involve prolonged sequences where Mitsuki desperately needs to urinate and cannot. More than once she gets manhandled (womanhandled?) by Hiyori to the point of orgasm. The story levels negative side effects on her for not pursuing a stepbrother that she doesn't want to be romantically or sexually interested in. Hiyori forces her into various awkward situations with Yuuya through possessions. This isn't fun and often isn't funny, despite the story's efforts to portray it otherwise, and Mitsuki's horrified reactions show that she is not inclined to just pass any of it off as harmless. In fact, that Mitsuki is allowed to show how uncomfortable she is with this treatment is rather curious, since it definitely detracts from accepting the content as the pure ecchi frivolity it seems to want to be.

Get away from the treatment of Mitsuki and what's left is a humdrum romantic comedy with occasional sparks of inspiration. Yuuya is the typically dense type who heavily misinterprets what is going on with Mitsuki and Hiyori (whom he sometime can see and sometimes cannot, with no revealed logic about why) but is generally a very considerate guy, while Yukina is the childhood “big sister” figure whom Hiyori sees as a romantic rival (and she may well be). No other girls are seriously in the romantic picture, so this is not a harem situation, but a hard-drinking aunt and Neko, a classmate who seems to know more about the situation than anyone else, are also involved, as is a friend of Yuuya's who is envious of Yuuya because he has a combative relationship with his own little sister. A definite mystery does surround Hiyori's forgotten past and why she is so obsessed with Yuuya, with the implication being that a scene depicted prominently in the closer as a joke might actually be the ironic truth, and at times the writing does elevates its quality a notch or two as it tries to explore the more serious aspects of Mitsuki's situation. However, as meat goes for basing a series recommendation on, such content is decidedly on the lean side and the effective humor is not plentiful enough to help.

The artistry certainly will not win over viewers, either. Nearly every aspect of it is, at best, average, and the character designs (by a first-time character designer) less so. A certain roughness to the designs, especially in how mouths and jaws are drawn and talking is animated, gives the designs a crude aesthetic that does not serve well attempts at fan service, and character rendering is too often rough and inconsistent. Aside from Hiyori's ever-present cleavage, attempts to make characters look sexy generally fall short, and the most intense aspects of the fan service content are more implied than shown; for instance, we do not see Mitsuki achieving orgasm but we definitely hear it. Background art looks okay, and in terms of showing movement the animation is passable, but overall this feels more like a rough draft of a show than a finished product. Perhaps not surprisingly, the production is also helmed by a first-time director and led by a studio whose only previous lead credit is Ro-Kyu-Bu!

The musical score does a little better, as it at least is not a detriment. It does what it can to salvage the humorous bits with appropriate ditties and generally light-hearted tunes occasionally supported by more ominous tones, but it underwhelms with its up-tempo but generic opener. Better – or at least catchier – is its closer “Charming Do,” which is probably most remarkable for its oddly (even creepily!) caricatured version of Hiyori and what it might or might not suggest about her past. Japanese voice work is solid, and the seiyuu do their best to make the most of content which often has little going for it.

Recently, my sister is unusual. is not a total disaster, but it stacks the deck strongly enough against itself that it stands in the lower echelons of otaku-oriented fan service titles. What little it has going for it is maddeningly short on elaboration, and the tepid end of the series suggests that at least another season will be required to get any real answers. A live-action version of the manga is due out shortly in Japan as of the time of this writing, which suggests that it may have enough drawing power to warrant a follow-up season. A first season of such dubious merit hardly makes for a good foundation for any more to come, however.