It's a virtual reality story where our heroines are anti-virus programs. They live in the "Box of Wisdom" and they eliminate viruses from its back-up data store. One day, though, a violet-haired piece of software called Rimo shows up and the girls can't work out her function. Rimo isn't telling, either. Instead she surprises the other two programs by setting out on an exploration of human concepts like beauty, cooking and music.

It's pretty and slightly underweight, but in a way that makes its length feel just right. How much could you take of a virtual reality slice-of-life with cute girls? An hour? Yeah, I can survive that. It's set in Not Real Land, but it's amiable and it's got an acceptable amount of Tron Existentialism.

If it were two hours, though? Club me to death with sticks.

Our heroines are Dual (who's sensible) and Dorothy (who keeps wanting to kill Rimo in case she's a virus). Dorothy thinks that Dual's problem is that she gets emotionally attached to the infected worlds they have to delete. Dorothy's a bit stupid and bloodthirsty, as well as often wearing distracting outfits, but she's nice once you've convinced her that it's okay to let you live.

The good news is that the film isn't just an hour of "why am I watching this?", i.e. empty virtual reality. Firstly, it has the worlds. Dual and Dorothy visit worlds in the back-up data, which for all we know contain clues to what happened in the real world outside. It's also kind of chilling, in an abstract way. "This world was born just this minute, along with everyone in it." Those people in it seem as real as anyone else, but Dual and Dorothy are quite likely to have created them in order to kill them.

Secondly, there's also the question of reality. What's happened? If you were a computer program, how would you find out? Does time even go at normal speed for Dual and Dorothy? They're familiar with that concept, since time behaves differently when they're inside the worlds they create.

It's an odd piece and not easy to characterise. It looks nice. It seems light, but its material is actually quite heavy. Some people have called it too short, but I thought it was exactly the right length given that it's basically an hour-long philosophy debate from the point of view of computer software. If it has a flaw, it's the weak-ish ending. It presents a bunch of ideas and concepts, then sort of stops. At the same time, though, it's a film about cute girls doing cute things, but with the twist that they're not girls and they don't understand "cute", instead having to rationalise it to themselves with "if I think it's delicious, then is it delicious?" That's something they'll have to explore and discover for themselves, if they think they need that information at all. "I have no interest in human culture."

It's okay. I found it beautiful and interesting, but I'm not convinced that it quite manages to take its ideas to a conclusion. I also don't think I'd recommend it. It's a rental, not a keeper. However I'll always have a soft spot for curious little oddities like this.