Mamoru Oshii's "Ghost in the Shell" is masterly Japanimation, a cyber-tech thriller that's miles ahead of such recent live-action cyber-splatter films as "Johnny Mnemonic." In look and spirit, "Ghost" is much closer to "Blade Runner," another moody post-apocalypse fable involving sentient cyborgs and their will to live.

Based on the popular comic books by Masamune Shirow, "Ghost" is set in 2029, a Net-dominated future where neighborhoods have been replaced by virtual environments and there's an uneasy alliance between humans and their "augmented" selves. Oshii doesn't waste much time setting up the logistics of his future: He simply steps into it so matter-of-factly that the viewer is swept away by the deft combination of action and imagination.

Section 6 (the Ministry of Foreign Affairs) has covertly created the perfect spy, a virtual agent dubbed the Puppet Master. It's the spy in the ointment: Without a physical body, it surfs the world's databases, wreaking political and economic havoc through data manipulation. But along the way, the Puppet Master decides to seek "political asylum" and "true physical existence" outside the Net. It wants to be some body.

Meanwhile, Section 9 (the Internal Bureau of Investigations) has a Shell team chasing the Puppet Master, believing it to be a particularly devious and dangerous techno-terrorist. Shells are semi-cybernetic humans like Maj. Motoko Kusanagi, who, except for a small part of her brain, has an almost wholly robotized body (often toplessly on display). She and her brawny partner, Bateau, experience many violent encounters on their way to the truth, and the moral dilemma Kusanagi faces at film's end is as thought-provoking as it is gut-wrenching.

The "ghost" of the title refers to false memories implanted in cyborg circuitry to provide the illusion of a past life. It also applies to the soul that's left as man is turned into machine. The dichotomy of memory and data is just one of many serious concepts that crop up in a film that has no problem mixing plentiful action with philosophic discourse.

Technically, "Ghost in the Shell" is astonishing, not only for its smooth meld of cell animation and state-of-the-art computer animation, but also for its imaginative storytelling and mood-setting (thanks to an eerie, non-thumping score by Kenji Kawai). Like Ridley Scott in "Blade Runner," Oshii and his companions have created a unique world, one they bring to life through patient exposition with great attention to detail and depth. You'll believe it when you see it, and you'll get caught up in the drama of it all as well.

Ghost in the Shell, at the Key, is not rated but contains animated nudity and graphic violence. CAPTION: Maj. Motoko Kusanagi, a semi-cybernetic human or Shell, who fights her way to the truth.