Think of "Blade Runner" as re-imagined by the very best of the Disney animators lounging in a steam bath, high on sake and yakuza movies, and you get some sense of the recondite pleasures to be found in Mamoru Oshii's "Ghost in the Shell 2: Innocence."

This spectacular sequel to Oshii's 1996 "Ghost in the Shell" may not be quite as good as the first, but it's still a trip to a universe almost impossible to describe yet so vivid that once you've visited, you'll never forget.

That's the universe of anime, the peculiar form of Japanese animation that takes as its first principle the idea that grown-up movies, not just kiddie fare, can be animated. Traditional cel and new computer-generated imagery are combined to dazzling effect. The ideas are as provocative as the art that expresses them, pondering the meanings of larger systems, loyalty and humanity, and expressing those meanings in adult-level discourse. Extreme violence is not unusual.

The adultification of the animated form is a largely radical concept for the rest of the world, but it's old news in Japan, where a whole culture of films, from the sappiest kid movies to hyper-violent samurai and gangster works to unbearably cruel hard-core porn, regularly arrives on screens in animated form. Unless we look hard, we only occasionally see the top-end material, like Oshii's, but it's part of a larger culture that takes stories told in pictures seriously.

Oshii is generally regarded, on the strength of his breakout film, the original "Ghost," to be at the apex of the pyramid. That film introduced millions to the form with its tale of Major Motoko, a female law-enforcement cyborg (part human, part robot) who tracks a rogue program called "The Puppet Master" through the hellish Tokyo of the 2030s. Assisted by two sidekicks, the top-kick-type Bateau and the new kid Togusa, the film races from shootout to murder to a final Gotterdammerung in the ruins, with Major Motoko facing some kind of super-armored vehicle, without backup. (In anime, nobody waits for backup!) It ends with a "2001" conceit: She is absorbed into the cyberspace she was meant to police, and is somehow "reborn" (like the star child) as an independent program. I think. Hmm, I'm not sure I'm the fellow to tell you what that means.

In this latest film, Bateau, blond and hulking with some sort of solenoid buried in the back of his neck -- he looks like a steroid-pumped Sgt. Rock who's swallowed a transistor radio -- moves over to take the hero's role, and Togusa becomes sidekick instead of sidekick's sidekick. But Motoko is not gone: Bateau knows she's there somewhere, in the free electrons of the Net, watching, waiting to come out and help him in some way. The "reunion" between these two semi-demi-quasi-human figures (the "ghost" in the shell of the titles refers to human emotions and reactions still left in cyborgs) is something the forlorn Bateau yearns for, though he's not sure why. (Could it be . . . love?)

But what gets "Innocence" off and rolling is a plot situation not unlike that of "Blade Runner": a hunt for some potentially homicidal gynoids (female pleasure robots; they were called "replicants" in "Blade Runner"). These creatures, meant primarily for sexual use, have suddenly begun fritzing out, killing their owners and disappearing. Since this could be a national security issue, Bateau's elite Section 9 is called to investigate. When Bateau attempts to arrest a killer gynoid, his 12-gauge shotgun reacts more quickly than his mind, and we get spattered solenoids and gizmos, rather than a "living" suspect. Bateau and Togusa poke their way through Tokyo, investigating the gynoid series of cyborgs (in a brilliantly conceived mechanical autopsy scene!), and go to a yakuza lair, where the guns come out and spray lead and blood everywhere. At some point, you can be forgiven for thinking that the ghost in the shell isn't Major Motoko's, but Sam Peckinpah's.

There are other stylistic influences as well. As "Ghost in the Shell" is to some degree an extract of "Blade Runner," it assumes the 1982 film's obsession with noir stylings and is big on haunted cityscapes and signifiers of that aesthetic, including rain, reflection, refracted light sources, cobblestones, the heavy ooze of cigarette smoke in the air. There's also a fondness for a certain type: The hard-boiled loner with a kind of poetic style, a love of metaphor. Bateau, lonely and ironic, is a kind of mechanistic Philip Marlowe. He's widely read, always quoting from either Eastern or Western literature the apposite Deep Thought; sometimes the movie -- particularly when Bateau is interviewing an educated witness -- sounds like a game of drunken Can You Top This? played by Oxford dons in a pub on a rainy night.

But ultimately, after various Tokyo adventures, Bateau and Togusa head north to a desolate zone where the gynoids themselves are manufactured. This is a typical anime landscape, at once fabulous and menacing, and like Ridley Scott in "Blade Runner," Oshii occasionally stops the forward motion of the story to simply indulge in the pleasures of spectacle, at one point halting the action as a parade of ghostly apparitions thunders down city streets, drawn from dreams of Japanese culture. It's stunning but ultimately irrelevant.

The track eventually takes the two to the gynoid plant itself, on board a ship in a poison sea: more rat-a-tat-tat! This time, the heroic Bateau finds himself joined by an unusual ally in the final shipboard shootout.

"Ghost in the Shell 2: Innocence" loves to examine the line between human and machine. This may not be the most promising area of speculation -- the line between human and animal seems far more provocative to me -- but the director uses it to power an extraordinary journey. Although this film doesn't quite have the down 'n' dirty dynamism of the first, and although we miss the fabulous Major Motoko, it's still a brilliant piece of filmmaking.

Ghost in the Shell 2: Innocence (93 minutes, at area theaters) is rated PG-13 for adult themes and images, including violence.

Mamoru Oshii's sequel takes another trip to a universe almost impossible to describe yet unforgettably vivid.