On paper, Ghost Cat Anzu would seem to be this year's most family-friendly offering at the annual Scotland Loves Anime Film Festival, now in its 15th year. Compared to most other films, the audience was certainly composed of a higher proportion of families with children. Perhaps they weren't expecting such a deeply strange movie, with a first half structured of loosely associated, scatalogically humorous skits and a second, more action-packed half descending into a chaotic exploration of Buddhist Hell, complete with violent comedy torture demons and deeply unsettling afterlife implications for at least one central character. We go from funny cat man licking his balls to “Needle Mountain Hell” and “Great Screaming Hell” within a matter of minutes.

Ghost Cat Anzu is bonkers, and I love it for that.

It's not only the unhinged plot that sets Ghost Cat Anzu apart. For one, it's a French-Japanese co-production and an adaptation of a relatively obscure single-volume 17-year-old manga (though a sequel began serialization earlier this year). Screenwriter Shinji Imaoka is best known for his work on several sexually explicit “pink films,” a brave choice for a “family” movie. Unusually, Ghost Cat Anzu has two directors because, in The Case of Hana and Alice-style, the film was first shot with one director entirely in live-action, then digitally painted over under the aegis of an animation director. I'd hesitate to call the animation style pure rotoscoping, however – while the characters do move in a more naturalistic fashion than in much other anime, it's not distracting or deliberately provocative like Flowers of Evil, which reveled in its naturalistic ugliness. Here, the live-action performances are transformed not into something uncanny or disconcerting, but human and relatable, even fantastical.

Take Karin – she's a brat. Manipulative and conniving, she's not a “nice” kid, but then life hasn't been “nice” to her. We quickly learn that she changes her demeanor depending on the audience. With her father, she's rude and condescending, referring to him only by his given name and with no honorifics. Around other adults, such as her grandad, she's all wide eyes and broad smiles as she pretends to be a “good girl.” It's funny and a little sad how she uses the blushing village boys to pursue her vindictive agendas. The animation style captures every nuance of her body language, adding to our understanding of her conflicted, complex character. Her facial expressions, in particular, are hilarious. It's unusual for a child in this animation genre to be so thoroughly fleshed out – she's an excellent example of a character who acts hatefully but remains empathetic for the audience.

Despite being a supernaturally-sized immortal “ghost cat” (a translation of the Japanese term “bakeneko”), Anzu himself acts more like a slightly weird, single, 37-year-old uncle with a penchant for Hawaiian shirts and farting loudly in public. His facial expression rarely changes – huge wide eyes that are difficult to read, emoting mainly by the liberal use of oddly-floating sweatdrops. He's hilariously flawed, getting pulled over by the police for riding a motorbike unlicensed and losing Karin's money at pachinko. At times, he's the unfair target of Karin's resentment, but as part of her family, he loves and looks out for her, making sacrifices and suffering for her wellbeing. He's a good kitty, really.

Anzu's not the only strange creature. In this version of rural Japan, the supernatural is but another aspect of everyday life – hence, when we meet various yokai, they're engaged in normal human activities, and no one bats an eyelid. Of course, a tanuki can work as a golf caddy, and obviously, a human-sized frog digs enormous holes and runs his own private hot spring pool. There's a gaggle of cute little spherical tree sprite birdie thingies that stepped straight out of a Miyazaki movie and a really weird-looking mushroom guy that adds to the extremely colorful supporting cast.

While Anzu's daft antics raised a great deal of laughter from among the festival audience, it's a slowly-paced film with strange comedic timing, where it takes a long time for anything to happen. That's not necessarily a criticism; many writers and directors have made entire careers producing slice-of-life anime celebrating the pleasures of a slow life. So it's unexpected that Ghost Cat Anzu goes to such exotic – and disturbing – places in its second half – switching up bucolic country existence first for urban Tokyo and then for the various levels of Buddhist Hell, here depicted as an upmarket hotel populated by Chinese-style demons and the souls of the dead. Comparisons with Keiichi Hara's Colorful spring to mind, with newly-deceased humans queueing up to receive details of their souls' fate from businesslike attendants.

I don't want to spoil the details of why the characters end up in hell or what they do there, but the film culminates in a truly demented car chase involving a minibus full of demons, Anzu demonstrating his most dangerous motorcycling skills, and an insanely-animated yokai-driven sports car sequence. It's all so silly, and while wonderfully fun for adults, there's a tonally discomforting element of quite brutal violence, played apparently for laughs. It may be too much for younger kids, and the ultimate outcome of these events may lead to challenging conversations with questioning children about Eastern concepts of the afterlife that may require entering a Wikipedia Death Spiral for parents.

At its core, Ghost Cat Anzu is a film about a young girl struggling with the scars that death has inflicted on her life, lashing out in anger and resentment at those around her, bargaining in an attempt to change her situation, and finding a way to gain acceptance. Indeed, there's some denial mixed up in there somewhere, too. Ghost Cat Anzu's ending will spark disagreements among viewers, as many aspects are left ambiguous, even though the central conflicts are satisfyingly resolved. It's absolutely not the sort of animated film you'd expect to see from a Western studio.

Even if you're not a fan of rotoscoped animation, don't let that put you off Ghost Cat Anzu. It's a deeply strange but entertaining film that, although it seems to start as a silly comedy, proves to be profoundly emotionally intelligent and interesting. Karin makes for a compelling and conflicted lead, ably supported by her charismatic and weird cat-uncle. Recommended for fans of Japanese folklore, “difficult” girls, and fart jokes. Nya-ha-ha-ha!