Streaming worldwide on Crunchyroll on the day of their Japanese theatrical release, does the distribution pattern of these one-hour-long thematically-linked movies mark a new strategy for the Sony-owned service? I can't see anything similar happening with massive properties like Demon Slayer or Jujutsu Kaisen. Perhaps this is a good way to attract as many viewers as possible for more obscure anime films with little chance of widespread Western theatrical release?

I went into this pair of films completely blind, unsure what to expect. I assumed them to be linked, perhaps by shared characters or at least a setting, but their relationship seems purely thematic. Both concern large towns with secret underground labyrinths beneath them. First-time feature director Shigeyoshi Tsukahara is credited as the original creator and screenwriter for both films, while Kuramerukagari appears to have also been created in tandem with a light novel by Ryohgo Narita.

Immediately apparent are the unusual aesthetic choices made by Tsukahara, consistent across both movies – a permanent, grimy grain effect that looks like someone smeared dirt across the camera lens. Combined with an earthy, oversaturated color palette, everything looks murky, which I'm sure is deliberate. While the delightfully simple character designs are striking (I particularly like glasses/pigtails combo girl Tomeomi and mysterious gray-haired girl Tanne), the backgrounds are entirely CG – but of a mostly unobtrusive style. In the more claustrophobic tunnel and cave scenes, the camera moves freely around high-quality painted textured scenery, which generally looks good. This approach falls during the second film, in the wider scenes, where the town's blocky buildings look like a poorly rendered video game overworld, with 2D characters awkwardly composited on top.

The CG is used to excellent effect for the wonderfully retro steampunk mecha – some trains spout legs to leave their rails, an almost-cute bipedal tank that's more than a little reminiscent of a Star Wars AT-ST Walker and a whole menagerie of creepy metal critters attempting a revolution against their human creators. At some points in the second film, it's almost as if William Gibson had written Steamboy.

Plot-wise, Kurayukaba is the most coherent, though I still scratched my head towards its bizarre conclusion. Detective Soutarou complacently sends his kid sidekick Saki to enter "The Dark" beneath the town to investigate some recent disappearances, only to instantly regret this a sudden quick-cut later as he receives a ransom note for her. This discombobulating editing technique is used on at least two other occasions for mostly comedic effect but probably also to keep the runtime lean.

Soutarou disguises himself as one of the metal bucket-wearing "Laughing Mask" gang members (I have no idea how they see anything; there aren't any eye holes in their buckets) and infiltrates a secret underground city built in a massive abandoned reservoir. There, he's embroiled in a war between gang members and an armed police unit that uses armored trains and tanks that fire heavy artillery. Clearly, someone took law enforcement tactics from Dominion Tank Police rather too seriously… The whole thing is a lot of daft, over-the-top fun with great action sequences. The plot becomes very strange, with suppressed memories and mass hypnosis machines that transmit freaky pictures into the sky, but overall, it's a good time.

I'd have loved to have spent more time with Kurayukaba's fun cast of characters, but unfortunately, Kuramerukagari features an entirely different setting and a different collection of underground-dwelling weirdos. This cast is larger and less well-integrated. The cool-looking Secret Service lady (I never caught her name) just wanders around with her goofy, bespectacled friend and gets into trouble, completely separately from the rest of the cast. Maybe I misunderstood, but I could not understand her purpose.

Kuramerukagari's plot takes forever to get going, which isn't great when its time is so limited, and I never felt I got a handle on anyone's motivations, other than main character Kagari (she likes cartographer/mapper boy Yuya) and Yuya, who wants a better future for himself and Kagari. Unfortunately, Yuya's method of wage earning involves selling up-to-date maps to the bad guys who want to unleash an army of banned automatons to… I don't know. Make a bid for world domination or something? It's not completely clear.

Anyway, there's a cool librarian dude who's an "information broker." His library has an automated book-sorting system I'd love to have in my book-infested home. He seems to know everything happening, but his explanations always stop short: "I could go on, but you'd need to pay me." Perhaps the production committee cheaped out on the "decent plot exposition" fee. Old Man Kuchinawa is another entertaining character whose metallic creations embark on an automata war to protect everyone from the marauding metal monstrosities – at least one of which looks like a Victorian-era Ghost in the Shell Tachikoma, while another sports a terrifying buzz-saw accessory.

Once again, there are some striking visuals in Kuramerukagari, but they're in service to a plot that's both overstuffed and underdeveloped. By the time the credits rolled, I couldn't say I understood why anything had happened. I feel the script could have been done with extra cooking time. While both films are worth watching, Kurayukabais most certainly the superior of the two. As the links between them are so tenuous, it's possible to watch only Kurayukabaand be quite satisfied. I'll be interested to see what director Shigeyoshi Tsukahara does next.