This 12 episode ONA series is a Netflix exclusive which debuted worldwide on that service on February 6th of this year. It is based on a manga of the same name which originally was posted online from 2005 to 2013 before being released in print form in 2016; an English language translation is expected to debut later this year. It is a title which arrives with little fanfare despite being directed by Koichi Chigira, who has a few notable directorial credits (Full Metal Panic! and Last Exile, among others) and being animated by newly-formed Studio KAI, which is an offshoot of GONZO. After seeing the whole thing, I have doubts that it could have been a big hit even if it had been better-advertised or released in a more conventional way. It's not a bad series, but it does not do much to distinguish itself, either.

One early make-or-break point for the series is its distinctive art style. It is rendered entirely in 3DCG, and this is definitely not one of the finest CG animation jobs out there. Neither is it among the worst; low-to-mid-grade 3DCG animation from Japan is distinctly better now than a few years ago. Among the production's stronger points is its action animation and the animation of the bugs (especially in distance shots), though the designs of the bugs leave a lot to be desired; the artistic team seems to be taking the notion of “bug-eyed” to extremes while also trying to fit skulls on them that are ugly amalgamations of bug and human characteristics, and that alone could be enough to drive some potential viewers away. Animation of humans does not look quite as awkward as in some other recent 3DCG titles, though it still has its flaws, but character depictions (especially in close-ups) can be unexpectedly rough in places. To put it another way, I tend to be more tolerant than most of 3DCG animation and the look of this one still took a while for me to get used to it.

Get past the visuals and the story is mostly a standard post-apocalyptic yarn flavored with elements of classic giant bug movies. The main difference is that the bugs are people – or were, anyway. One of the more interesting details is that this necessitates quantifying exactly when a person stops being human and thus can be killed without concern for laws or morality; do it too soon in the transformation process and it still counts as murder, but once wings sprout the transforming person is no longer considered a person. This is a guideline that has been laid down to prevent Exterminators from abusing their authority to kill Cagasters, and that Kidow has some struggles with this despite thinking he's conditioned himself to be heartless provides at least some depth to his characterization. That only certain people carry the gene which makes them vulnerable to being transformed by the virus becomes a big point later in the story as the main villain's motives crystallize: he seeks to force the transformation of all of those vulnerable to it so that they can be weeded out and only a world for untainted humans left behind. Apparently widespread genetic testing is no longer feasible in this setting. . .

Otherwise this is essentially a story about a young man who's more normal than he'd like to think he is and the girl he gets mixed up with who's less normal than she likes to think she is. A few other characters figure in prominently, including a very masculine transgender tavern operator, a pack of orphans that Ilie makes friends with, a soldier who's rough on Exterminators but looks out for the orphans, a sociopathic scientist who may be deeply connected to Ilie (and plays a much bigger role in the second half), and a boy who only partially transformed into a Cagaster; he's basically equivalent to the Kabaneri in Kabaneri of the Iron Fortress, a series which this one has at least a few things in common with. But the whole story keeps coming back to the connection that Kidow and Ilie gradually make, with occasional more poignant moments also coming from other characters; for any other faults the series may have, it is surprisingly effective at this, especially concerning the final fates of the aforementioned soldier and Ilie's biological parents.

The series is also quite graphic. It shows a pronounced penchant for dramatic blood sprays and features numerous gruesome death and transformation scenes, with decapitations and impalements being regular features. While the content is not on the level of the most intense titles out there, it is only one step down from that. Netflix is rating the series MA with a Nudity notice, but that is overstated; there's only maybe two brief scenes in the series which could count as nudity and neither one really shows anything. Fan service is otherwise basically nonexistent.

The musical score for the series is solid but nothing special. It capably build tension and softens for gentler moments by using a mix of synthesized and instrumental pieces; if it never stands out, at least it is doing its job. Opener “Be Zero,” which is obsessed with blow-ups of microscopic insects as key visuals, is one of the least appealing openers that I have encountered in quite some time, but closer “Cowardly Wolf 2019” is fine.

Netflix used VSI Los Angeles (the same studio which recently did the new dub for Millennium Actress) to produce the English dub, in addition to the regular complement of dubs in other languages. Aleks Le and Ryan Bartley both fit well in the lead roles as Kidow and Ilie, respectively, while Kim Strauss (Keiki in The Twelve Kingdoms, though he sounds quite different here) handles Mario just fine without resorting to any colorful stereotyping. Other roles impress less but are at least acceptable.

On the whole, Cagaster of an Insect Cage flirts at times with being a much better series, as it has moments where the storytelling, music, pacing, and sense of visual staging come together in a highly synergistic fashion. Unfortunately it does not have enough of those moments to elevate the series as a whole to a higher level. Still, as bug hunts go, you could definitely do worse.