Crayon Shin-chan's pretty famous, but this was the first time I'd seen any of his anime. Shin-chan is a vulgar brat who talks to his family in a rude way (using their names without honorifics), does stupid things and likes dropping his trousers and waving his bare bottom in the air. He's also five years old and tiny, not even reaching adults' knees.

Oh, and the art looks as if the artist was drunk, or possibly five years old too.

This is a kung fu Shin-chan film and I thought it was great. The vulgarity and low gags turn it into a massive genre subversion. It's a proper kung fu movie, but one where the final battles are fought by bottom-wiggling and by Shin-chan doing a daft song-and-dance number.

The first half-hour feels inconsequential. It's just Shin-chan and his friends messing around. Masao's discovered kung fu, so everyone goes off to Chinatown to meet his sensei. There's an awesome elderly Chinese bun seller with a bad back who can wibble-wobble his way through a fight with multiple serious opponents. His weapon is Puni Puni Kung Fu. (You can think of this as Squishy-Wishy or Wibbly-Wobbly.) It turns out that Shin-chan is gifted at this, being a lazy blob with prehensile buttocks. (He can catch falling food items with his arse cheeks.)

We also meet Grandad's apprentice, Ran, a woman who was abandoned in Chinatown as a baby. ("This town raised me.") You'll like Ran. Our five-year-old heroes decide to do kung fu and soon they're learning unconventional moves like:

1. KISS LIKE A SUCKER, in which you cling to walls with your lips.

2. WOBBLE YOUR BODY LIKE SEAWEED

3. CRAWL LIKE A CATERPILLAR

4. Break your fall by pretending you wanted to be down on the ground all along, to watch ants.

This is amusing, but after a while you realise that there's a plot! There's an evil company called Black Panda Ramen, run by a phone-eating baddie who's like an evil comedy Kenshin from Fist of the North Star. He can poke pressure points in your head that can make you walk like a crab, or else never stop saying "we like totally see your knickers". (The film eventually turns the latter into an unusual language.)

If you eat Black Panda Ramen, you'll get dark circles under your eyes and turn into an irritable, ramen-crazed zombie. Fortunately your bite isn't infectious. (The only thing you'll want to put in your mouth is ramen.) However the company's expanding so rapidly that there's soon an army of violent, obnoxious ramen addicts.

Our heroes must: (a) stop these guys, and (b) cope with Shin-chan's personality! (He only realises that the baddie's bad when there's a threat to Shin-chan's food, while later he can't be bothered learning the ultimate martial arts move in order to save the world. There's something he wanted to watch on TV, you see.)

I love it. It's a proper kung fu film, with a proper plot, but at the same time everything about it is bonkers. The baddies win (!), but then our heroes sneak into their ramen factory. There's an entire third act after the baddie's been defeated. I was impressed. It's better than a straight martial arts film, although I'm sure lots of this has been done a million times in other Crayon Shin-chan films (e.g. Shin-chan's father's smelly sock attack).

There's dog poo and wee. There's guitar fu that's even sillier than you're imagining. This film is cool.