Yagyu Jubei Mitsuyoshi was a 17th century samurai and the son of a master swordsman. He was a child attendant in the court of the second Tokugawa shogun, wrote a treatise on swordsmanship and other teachings and died in uncertain circumstances in his early forties. Mysteriously he's since become a giant of Japanese popular culture, perhaps because so little is known about his life. He went on a Warrior's Pilgrimage in 1631 and disappeared from sight for twelve years, which seems to have obsessed modern authors, artists and filmmakers. He's appeared in many movies, not to mention manga, anime and video games like Ninja Resurrection, Lone Wolf and Cub and Yaiba. It's also said that he only had one eye, traditionally said to have been lost in a practice battle with his father, and wore an eyepatch.

Jubei-Chan adds a new dimension to the legend by revealing that his eyepatch was heart-shaped and pink.

The story begins with Yagyu Jubei fatally wounded after a forest duel. His dying wish is for his school of swordsmanship to be entrusted to a worthy successor, forging a new generation of warriors. His faithful servant Koinosuke swears to do whatever it takes to bring this about. Who should this fighter be? Yagyu Jubei's main criterion is "nice arse". Three centuries later, the somewhat haggard Koinosuke finally sees his dream arse on a teenage girl called Nanohana Jiyu. Almost dribbling with joy he gives her the eyepatch which will transform her into the reincarnation of an invincible samurai... and that's not even the weirdest thing in her life that day. That would be her dad.

In case you hadn't already realised, Jubei-Chan: Secret of the Lovely Eyepatch isn't entirely serious. However you can't dismiss it as dumb comedy either. It's an extraordinary show, starting off so shallow and brainless that I could only assume it was deliberate to wrong-foot the audience. We got cheap gags, ridiculous artwork and villains of the week. The first few episodes looked like the kind of formulaic filler one gets in 200-episode epics like Sailor Moon, not little thirteen-parters. It was cute and funny, but seemingly no more.

Then the story started building. I've never seen anything go such huge distances, turning loopy comedy into serious drama. Stupid and/or annoying characters are transformed into something worthwhile. You'd think it was a deliberate experiment.

Two words explain everything: Akitaroh Daichi, my all-time favourite director. Fruits Basket and Kodocha proved that no one alive has a greater command of tone. I remember scenes in Kodocha which had me on the floor with laughter but then seconds later almost in tears, with transitions so subtle as to be almost invisible. It's masterly. I've never seen anyone shift between comedy and drama so effortlessly, using each to counterpoint the other. He can do things in moments which some directors couldn't pull off in a full episode.

Jubei-Chan isn't one of Akitaroh's top-tier works, mostly because it pushes the envelope even by his standards. It's prepared to stretch reality much further than those other two series. It has cartoonishness, fourth wall jokes and deliberate experimentation with anime cliches. The opening episodes feel dumb. It's easy to wring drama from impassioned characters in a life-or-death situation. Far harder is the challenge of wringing drama from a show that started out pretending to come from a kiddie cartoon factory on the day they overdosed on happy pills. I'm imagining a runner who's getting bored of marathons, so decides to tackle the next one wearing a ball and chain. I admire Jubei-Chan tremendously, but it's a unique kind of achievement.

It's doubly hard to nail down because Akitaroh's comic timing is so good that sometimes you're laughing at the straight scenes. I normally hate fourth wall jokes, but here they work. I also like the art by Madhouse, which is well up to their usual standards. It's not photorealism, but it's not anime's usual style either. It's lovely simple work, with rounded soft lines that make it feel like a cartoon. Jubei-chan for instance looks adorable without being the exaggerated fantasy of a thirteen-year-old. That's its usual style, but there are extreme departures from it. Some comedy reaction shots have distractingly overdone black lines. Some characters look so absurd as to be inhuman, e.g. Hajime's mum, while part four's villain is a crayon scribble. On both a visual and a story level, this show is pushing the boundaries. I admire its adventurousness, but I can see how it might turn other people off.

The swordfights look great, though. Yagyu Jubei doesn't waste time with posing or dramatic speeches, but invariably gets straight to business.

The characters are interesting, sometimes despite first impressions. Jubei-chan initially seems to be no more than an ordinary cute girl among weirdos. (Every male in the show is certifiable.) She's always cheerful and happy, but more in a Teflon-coated way than like the determination of, say, Fruits Basket's Tohru Honda. She's so easy-going as to have almost a goldfish memory. However as the series progresses we learn better. Jubei-chan may look like an airhead but in fact she's surprisingly clear-thinking, giving an impressively reasoned response to Koinosuke's claim that it's her duty to kick arse. One thing in particular is clear: she doesn't want the Lovely Eyepatch. She doesn't make a big fuss about it because that's not her way, but she has no desire to don a dorky pirate's accessory, become a dead samurai and fight people. Unfortunately that's exactly what she's going to have to do.

Only at the halfway point do we see the light. Jubei-chan's a strong character. She's not care-resistant. It's just incredibly hard to piss her off. She's determined to be her own girl and has thus constructed a cheerful serenity from which almost everything bounces without the slightest impact.

Some of the characters are wonderful from the beginning, e.g. Koinosuke and Jubei-chan's father, but others took a while to grow on me. The three Ruffians were initially annoying, though after a while I realised that their leader's monkey-like henchmen were as aware as me of his uselessness. Their sideswipes at their boss can be funny. However if I had to choose one thing, this show's worth watching just to hear the unbelievable voices of the handmaidens of Miss Otome Shirahatamaru.

It shares themes with Akitaroh Daichi's other series. Parenthood is one, especially father-daughter bonding. Akitaroh's mothers tend to get the short end of the stick. There's also his running motif that professional writers are kind-hearted lunatics with quirks and flaws so extreme that they don't so much interact with the real world as hold it at bay through sheer force of personality.

This show never stopped surprising me. Even the finale wasn't what I expected. The all-action climax is a little weak, since The Hero Resists The Challenge is an expected part of stories these days (it's in Campbell and everything) and sadly one had never doubted that Jubei-chan will end up having to accept the Lovely Eyepatch. Her determination not to do so thus never got the weight it deserved. The climax lacks something unless you've carefully remembered how adamant Jubei was about not donning the eyepatch in those early episodes, and the show doesn't remind you. However that's only half the story. Thereafter the show's conclusion goes in directions that surprised me even after I'd experienced the previous twelve episodes and was an Akitaroh Daichi fan to boot.

Incidentally, this show's Western title is "Jubei-Chan the Ninja Girl: Secret of the Lovely Eyepatch". We won't have heard of Yagyu Jubei, so "Jubei-Chan" (the rough equivalent of "Jubei-Sweetie") doesn't mean anything to us. You can see why they added the "Ninja Girl", except that unfortunately Yagyu wasn't a ninja but a samurai. Huh? I suppose "ninja" sounds cooler or something.

This show is an experience. It does things you'll never see anywhere else, including a few that you might not want to. However it's unmistakably the work of Akitaroh Daichi and for that from me gets top marks. You wouldn't believe the things he does with wacky gag effects, or how much you'll end up caring about his comedy characters. It can be silly, hilarious or moving, sometimes all at once in the same scene. There's even a sequel series, Jubei-Chan 2: The Counterattack of Siberia Yagyu. This show would probably be regarded by most people as a mere curiosity, but this kind of thing is why I watch anime.