If you are considering reading Semelparous strictly for the yuri content, there are a few things you should be aware of. The main one is that this is one of those yuri titles that goes in for some truly ridiculous breast physics and male gaze trappings – obviously not all lesbian romances are written with all potential readers in mind, but the balloon boobs and the fact that "sharing aegis" requires putting your hand on the other person's heart – which in this series is apparently located around the nipple – is a bit much. It feels more like the book is interested in gratuitous girl-on-girl groping than in exploring or creating a relationship, and while that's not necessarily a deal-breaker, it also may make this a title more appealing to readers of Attack on Titan knock-offs and dark science fiction than the dedicated yuri fanbase.

And it does feel like a bit of an AOT knock-off, make no mistake. This is mostly due to the creature design of the monsters, known as kaiju. Don't let the name fool you – these are less Gamera and more a cross between the Titans (from Attack on Titan, of course) and the Hollows from Bleach, and they're hiding a truly disturbing secret inside of them...which may be less disturbing if you've read AOT. In fact, it's a bit difficult to find anything truly original in this work, which honestly sounds more damning than it turns out to be in practice. The basic set up of the world is that the real one, an alternate version of our own, is separated from a parallel world where history took a slightly different path by two walls sandwiching an otherworld known as the interspace. Kaiju, for reasons currently unknown, frequently try to break through the walls to invade the real world (which to them must be the parallel), and it is up to those with the hereditary power of aegis to fight them off in the interspace. Since the job is so important, those with aegis are trained from elementary school onwards, and once they graduate middle school they are able to join the fight for real, with the caveat that they attend high school, because how else would Ogino get school uniforms in there.

The story follows young bulwark (soldier) Yorino, whose best friend Haruka is killed defending her on their first foray into the interspace. Initially it was Haruka who was keen on the girls joining up; even though everyone with aegis must train, they aren't required to join the army, which is a nice change from the norm in this sort of series. It's also fairly common for young bulwarks to leave the service after only a few battles, which is probably the best bit of foreshadowing we get in the book and another good touch in making this distinct from other similar series. After Haruka's death, Yorino joins the bulwarks anyway out of a desire to avenge her friend, and she is paired with Youko, who very much has a crush on her. Although Yorino seems to have forgotten it, she and Youko attended the same elementary school, with Youko a few years ahead of her, something that seems as if it will come back into play later in the series.

At this point, Youko's crush on Yorino is mostly demonstrated via her touching Yorino more than the other girl is comfortable with and requesting Yorino for her partner, as all new recruits are paired with an older, more experienced bulwarks initially. While it doesn't precisely feel shoehorned in, the yuri is really window dressing to the science fiction/horror blend that makes up the plot. It's sort of a shame, because we don't get as much genre fiction with a serious yuri focus as we might, but it also may not remain the case forever – we got a real sense of the emotional attachment Yorino felt towards Haruka, so her relationship with Youko may evolve into something more than an excuse for the creator to draw girls smushing their boobs together or putting their hands on each other's “hearts.” And Youko does seem concerned about Yorino when she finds out the series' twist about the kaiju, which bodes well for the development of their relationship into something beyond fanservice.

The main issues with Semelparous are twofold: the art, and the feeling that we've read this story before under a different title. Since authors and manga creators alike have been known to jump on publishing bandwagons (see: the proliferation of stories set in the 1910s after Downton Abbey became popular or the many, many remakes of the Spanish TV series Grand Hotel), the art seems to me to be the bigger issue. In part this is because it exacerbates the similarities between it and other series, but the boob physics could also be a barrier for some readers – Jun Ogino seems to think that breasts are just bags of air that dangle off the chest. But there are also thigh gaps you could drive a truck through and action scenes that feel more stilted than they ought to, and those can detract from the overall experience of reading.

That's a shame, because there are some good elements to this book. Even if you see it strictly as an attempt to cash in on the popularity of other, similar series, the way that it handles its big reveal and Yoshino's reaction to it is effective, and it certainly makes us question how Yoshino will eventually react to it, especially when it comes to Haruka's death. Yoshino herself is shaping up to be a decent character, and if Youko doesn't come across the same way, this is only volume one and there's enough plot to make me at least curious about volume two. This isn't necessarily the book for you if you're more interested in the sort of yuri that gently explores the relationship between two women, or even just puts their relationship front and center. But it is still an interesting read, and if you can ignore the similarities to AOT and the issues with the art, it's at least worth checking out.