It's endearing, quirky and proud of its unimportance. The title says it all. Hiroshi is a goofy freeloader with no noticeable brains, but he's charming in his happy-go-lucky optimism and his ignorance of shame or restraint. He's child-like, except for the "sex machine" bit.

It's also a Japanese pink film. It's a movie that doesn't matter at all, but I quite liked it.

The director, Yuji Tajiri is one of the group of directors known as the Seven Lucky Gods of Pink. He's one of a younger generation, having been born in 1968. His directorial debut was Go Go Train (1997), after which his next movie Office Lady Love Juice (1999) not only won him Best Film of the year and Best Director at the Pink Grand Prix, but also non-porn recognition as the seventh best release of the year with the Japanese Film Professional's Award. So in other words, he's okay. He's not just a trash-meister.

This particular film stars Mutsuo Yoshioka as the title character, Rinako Hirasawa as a single mother who likes sex and her young son, played by a boy whose name I don't know. The character's name is Yuichiro, so that's what I'll call him too. There are other people too, but those are the most important... but arguably more important still are the crickets.

The film begins with those three on a bus, plus crickets. We see a magnificent close-up of one. Yuichiro has them in a box and they get loose when Yoshioka hits it. These creatures are beautiful, but more importantly they're the second engine of the plot (after sex). The main economic activity in this film is cricket sumo. It's the daily obsession of Hirasawa's neighbours, ex-husband and dodgy acquaintance (Kazuhiro Sano) with whom she occasionally has sex, although she doesn't seem to like him. Men fight through crickets and women have jobs. That's the way of the world. Hirasawa works in a post office, for instance, whereas Sano made so much money from crickets that it paid for his house. Yoshioka naturally gets into it too and soon has a cricket champion, so big and fierce that Yoshioka's planning to put him on a two-week fast. However in addition the insects also become a metaphor, when the men talk about how male crickets can be made to fight each other but the female crickets aren't interested and instead will eventually just eat their menfolk.

The men are losers, but despite this mostly likeable. Hirasawa's neighbours are Peeping Toms who'll masturbate outside her window, but not in a bad way. (You'll have to trust me on that.) Yoshioka is probably never going to have a job until the day he dies, but he doesn't even seem to have realised because his only interests are goofing off, masturbating and having sex with women. He gets on particularly well with Yuichiro, incidentally. If I were five years old, I'd think Yoshioka was awesome too. There's a charming throwaway of them singing into a fan together while Hirasawa plays her drum, for instance.

As for the sex, there's quite a lot. However it never overwhelms the story, instead just feeling like a movie that happens to have a lot of sex in it. We see pubic hair, which is unusual, but it's all softcore... although that said, Hirasawa's acting CV appears to be mostly hardcore porn, if you were looking for that. She's fine as an actress here, though.

Overall, it's light and amusing. Once or twice it even made me laugh, since Yoshioka is such a goofball. He's got the most wonderful face, looking as if he's never had a thought in his life, and I'm not surprised that he's done a ton of films and recently seems to have graduated from porn into the mainstream. (He's in Wife of GeGeGe, for instance.) People sleep around and for some reason I didn't mind, because the film creates such a frivolous, gentle world. It's not all lightweight, though. The men are bubbleheads, but the women are aware of their responsibilities and will ask deeper questions ("aren't you lonely?"). Hirasawa's useless ex-husband has a girlfriend, Minami Aiyama, who even brings a bit of emotional complexity to the movie.

The movie's humour is well-judged, I think. It has silly moments (e.g. the flying semen) but it gets away with them. It has wacky plot developments in the final act, not least of which is a moment where the ground ejaculates, but that's cool too. You'll also want to look out for a surprising use for a cucumber.

This is an utterly disposable movie, obviously. It's fluff that won't add anything to your life, but it'll make you smile. Somehow it feels appropriate that Hirasawa's outfit in the opening scene is a Pink Panther T-shirt. It's about music (Hirasawa's drum), goofing off and of course sex. More important than any of those things though are the crickets. The five-year-old is almost the most mature male in the film. It's like a Just William adaptation, but with shagging. You've got to admire a story that builds itself so wholeheartedly on foundations this silly, haven't you?