No spoilers. So, I went into this blind, and just from the title and date I wasn't expecting much. And in the beginning I sort of didn't know if I liked it. But the concepts were interesting and the execution seemed on the spot. So I stuck it out, and I am incredibly glad I did, as I'd say this is one of the best anime I've seen. The characters are all well-done and believable, without being too humanized for extradimensional aliens in human bodies. The show really manages to capture the sense of gravity in everyday interactions, and especially in interpersonal relationshipsfor these Rynax. Unlike so many other shows where the alien is just magically capable of human levels of expression, the sort of simplistic expression of emotions between Kurau and Christmas seem really true to form, and they maintain this truth to the character concept throughout the show. Some people may criticize the characters for being too expressionless, but I think there's a clear delineation drawn between Rynax and humans with that regard, and it really helps to impart some of the deeper ethical metaphor that the writers seem to be going for.

Speaking of metaphor, holy cow is this just filled to the brim! The Rynax having a sort of codependency upon their pair is reflected within the story brilliantly, with every instance of a metaphor being matched sometime later in the show by a reflection thereof. There are several overarching themes and conflict levels at play in the show, from the ethical question of beings too dangerous to exist to the metaphors for the manifold nature of human affection and reliance. And every time one is introduced, there's a duality to it, where it's represented in two ways which are complementary. This is by far the most impressive part of the show to me, is the ability of the authors to juggle so many different themes and philosophical conflicts at once, while keeping a reflection of each issue actively in play.

Art and sound were perfect but not too much. The muted nature of the art really allowed for more of a focus on the characters, while still being absolutely stunning in execution of action sequences. And much to my satisfaction, I didn't notice a scrap of ero-fanservice. The music was expertly chosen and used almost impeccably, with the lyrics themselves playing into the sort of dually-important theme that the show sets forth. Despite being used quite a few times over 24 episodes, I never got tired of hearing any of the songs, and they always seemed to fit perfectly.

I would highly recommend this anime for anyone who likes deep interpersonal relationships and who can delve into stuff with a really critical lens. I feel like a whole lot of the depth of this show could just pass right over peoples' heads. That might sound arrogant, but the show is very unassuming and themes are not used like a club but instead are left like one flower on your doorstep and another planted in your garden.