Sometimes a mediocre show is a good way to think about deeper things. Brave 10 is, by itself, nothing worth crossing the road for: it's an assembly line samurai/ninja fantasy (something I have a weakness for, I admit) with a storyline hijacked from Japanese legend, beaten to fit, and painted to match. But it did provoke some interesting reflections on the way Japan uses the supernatural and the fantastic to jazz up retellings of its own history that have since become shopworn.
First, the story itself. It is a loose — very, very loose — reworking of the story of the "Ten Heroes of Sanada", about a gang of ninja allegedly in the service of Yukimura Sanada during the Sengoku period. Most of the action revolves around one Kirigakure Saizou, an Iga-clan ninja with a loner streak (I've never known a ninja who was much of a team player, come to think of it), and Isanami, the shrine maiden he rescues from attackers. "Rescues" is only the most technical description of what he does, since he's not particularly moved by the idea of sticking his neck out for a woman.
Isanami, on the other hand, has no trouble imagining him in the hero role, since she could use a bodyguard to protect her. She's seeking the safety of Sanada's forces, since it was one of his rivals (Ieyasu Tokugawa, later ruler of all Japan) who burned down Isanami's shrine and murdered all of her fellows. Sanada, as it turns out, has good reason to have both Isanami and Saizou on his side, since he believes the two of them will help round out his roster of "Ten Braves", a gang of warriors who each embody a particular natural element. Isanami is surprised to discover she has a place in this gang of ten — to say nothing of Saizou — and they both learn the outer extent of each of their powers as the two of them face attacks from an increasingly vicious set of enemies.
Some of those enemies end up becoming other members of the Ten, and consequently many of these people hate each other's guts and spend at least as much time trying to stab each other in the back as they do getting anything done. It's up to the viewer to decide if this amounts to a) an additional degree of tension or b) mere tedium.
History, mutating itself
The current reigning king and emperor of all Japanese-history-through-the-looking-glass productions is, of course, Sengoku Basara, and I will most likely surprise no one by admitting up front I'm a colossal fan of that show. Its appeal can be summed up in a description I gave someone else: Imagine a movie about World War II where Roosevelt, Churchill, and Mussolini are all dogfighting in jet-powered zeppelins, and the climactic fight is a light-saber duel between Hitler and Stalin. Basara is at least as bonkers, perhaps even more so, and a big part of its appeal is how it manages to be so over-the-top and yet still compelling on a character level—maybe because the characters themselves are as larger-than-life as their setting.
What I always found a little irritating about the penchant for exotic anime re-takes of Japanese history was something I had to chalk up to my position as an outsider. By itself, unvarnished, Japanese history is already interesting enough: why gild a lily? But such shows are made for Japanese audiences, and those folks have already experienced so many permutations of the same stories that any variety is welcome. The more wild and stylized the variety, the better. Shows that only cover existing territory predictably are scorched earth.
This has been going on for many a decade — certainly since after WWII, when novelist Fūtaro Yamada not only gave us his mad twists on samurai legends but went a step further with them and essentially created the modern-day pop-culture mythology of the ninja as we currently know it. (See: Basilisk, directly derived from his writing — and also Naruto, of course, which would not exist without the likes of Yamada's work.) It's happened in Japan's fiction, in their live-action cinema, and of course anime and manga, and it's something that will continue to happen. In fact, I hope it continues to happen; when done right, it's a wonderfully creative way to build a story.
The problem is that just putting a supernatural / fantasy suit of clothes on that particular showroom dummy doesn't make it come to life. Basara worked not just because it was a fanciful take on history, but because of its manic energy and irrepressible style, and strong sense of character as an engine for a story. Brave 10 is more about dressing up the old story in just enough trappings to make it seem appealing to an audience that's been reared on fantasies that were in turn derived from the previous generation of such things.
So while the show works well enough to be an enjoyable distraction, it isn't able to do much else. The other things that most need to be there, like characters worth caring about, or a story that feels like more than just a retread of familiar material, have been glossed over a little too freely.