Samurai Spy, despite the generic title, is a solid piece of ninja/samurai espionage and suspense. The plot changes at a brisk pace, there are no slow moments, and the tale is accompanied by inventive music and gorgeous scenery. The story revolves around Sasuke Sarutobi, an agent for the prominent Sanada clan, one which has not publicly allied with either one of the feuding Toyotomi or Tokugawa families during early 17th century Japan. Through his friendship with a day-dreaming (and careless) fellow agent, he becomes linked to a dangerous conspiracy involving the feuding espionage directors of both feuding families.
I was initially going to downgrade the movie based on some clumsy fighting scenes, but some of the stylized action later in the film makes up for it. My main concern was the ridiculously slow and monotonous movements of the protagonist, Sarutobi Sasuke! So many people are killed by the same "daijodan", overhead sword strike -- and in slow motion! Ha, it's not quite up to par with other films from this period, i.e. Sword of the Beast, Sword of Doom, Sanjuro, Samurai Assassin, Samurai Rebellion, etc.
But don't be mistaken. It makes up for the lack of explosive early action with great espionage scenes, fantastic long-range cinematography and zooms, some serious tension in the final few battles, and -- as I mentioned before -- some good stylized ninja action. And there is a decent amount of action, too. It isn't necessarily dull or unbelievable.
The real meat of this piece comes from the plot twists, character development and social/political commentary. As the summary on the back of the Criterion box says, "no one is who they seem to be". The variety of characters, similarity of syllables among the names and historical setting might make this confusing for some folks who aren't "Otaku" (Japan-o-philes) but this is part of the immersion. As another user mentioned, the viewer is hanging onto the plot twists by a hair, much like the protagonist. But I was never TOO confused and found the plot to be ultimately rewarding. Trust me, it's nowhere near as complicated as Kinji Fukasaku's "Shogun's Samurai" (Yagyu Clan Conspiracy). That one requires some aspirin.
The story also has some hefty commentary on (or parallels to) the roles of espionage agents during the Cold War and their blatant disregard for human life in the constant quest for political self-profit. The ninjas here are generally depicted as stoic agents, emotionless tools of their superiors' quest for power. Their presence and deaths do leave some kind of poignant statement in being presented this way (or maybe it's just me?). Director Masahiro Shinoda says something related on the DVD interview: there's something poignant and more life-like to seeing a person die in battle. As though the person who lives, splattered by the other's blood, is actually somehow the loser.
Interesting stuff, with deeper thoughts than you might expect behind a political/ninja facade.
