"Blood Type Blue," a dithering science-fiction polemic booked to conclude a Japanese film series at the Biograph, is the latest undeniable contender for the Mind-Boggling Hall of Fame. Just the other day "The Passage" and "Hurricane" served to have the bottom of the barrel securely covered. Incredibly "Blood Type Blue" bottoms out at a subterranean level of confusion and ineptitute.

Scheduled for a one-week American premiere at the Biograph, the film appears to be the result of some debilitating mawkish brainstorm that overwhelmed the usually resourceful and vigorous action-director Kihachi Okamoto, known here for slashing, oddly sardonic samurai melodramas like "Sword of Doom" and "Tokkan." This dubious plunge into futuristic allegory exposes a strain of naivete that had suggested a low-budget Kurosawa period subjects.

At his most invigorating, Okamoto had suggested a low-budget Kurosawa, Evidently, the affinity extends to the sentimental side of Kurosawa that ultimately degenerated into the pitiful looniness of "Dodeskaden," his bewildering love song to the wretched and demented of the earth. With its scrambled elements of science-fiction, political paranoia and soggy social consciousness, "Blood Type Blue" is like a compilation of the dumbest scenes from "The Bermuda Triangle," "The Parallax View" and "Dodeskaden."

The premise might have inspired a decent science-fiction thriller. In the wake of UFO sightings, a strange new blood type has evolved. The phenomenon, affecting people who've sighted UFO's, appears to be world-wide. Although the only apparent change is in the color of their blood, could it signify something more ominous, like a catastrophic threat to the human race?

In a conscientious science-fiction thriller, it would. Okamoto exploits it clumsily as a political red - or blue - herring. The UFOs are supposed to be authentic and are the cause of the blue blood, allegedly using a "space beam" that "changes the iron in hemoglobin into copper."

After an hour and a half of helterskelter, baffling exposition, Okamoto abandons the apparent protagonist, Tatsuya Nakadai as a globetrotting stooge assigned to "investigate" the phenomenon by his employer, the Japanese Broadcasting Company. More or less admitting that he's been giving us a runaround, Okamoto switches to the pathetic tale of a stalwart soldier who falls in love with a blue-blooded virgin. He learns her secret on their first night of love but must round her up when the government decides to execute all blues.

The UFOs, it seems, were just being playful, while the color change was strictly cosmetic. The genuine threat comes from terrestrial figures of authority who cannot tolerate People Who are Different. Okamoto ends up equating the blues with the Jews persecuted by Hitler.

The equation won't add up, to put it gently. Okamoto confuses categories, genres, locations, clues and emotional impulses in a way that can produce only a muddle. One gathers that he intended "Blood Type Blue" to be a heart-rending plea for universal tolerance. Unfortunately, the message is transmitted in such an absurd, rattlebrained form that one ends up interpreting it as an embarrassing cry for help from a filmmaker stuck with a mess of a movie.