BOOK REVIEW: NOVEL : A Thriller Is Still Just a Thriller--Even When Set in Japan : THE TIME OF THE CRICKET <i> by William D. Blankenship</i> , Donald I. Fine, $21.50, 300 pages

The first thing we learn about Japan’s samurai swords is that even by modern standards, they are marvels of sophisticated steelmaking--strong enough to hack through armor, sharp enough to sever a spider’s web.

And we can’t help wondering at least briefly what it would be like to be a warrior in the age of the shoguns--or in a Kurosawa movie--charging into the enemy’s lines with such a sword and lopping off arms and heads.

This is the visceral hook William D. Blankenship uses to draw us into an otherwise undistinguished thriller about underworld influence and official corruption in today’s Tokyo.

Antiques expert Kay Williams (whose “flamboyant head of reddish-brown hair, stylish clothes and long tanned legs turned all heads, men and women alike”) arrives in Tokyo on behalf of a rich American collector to buy a sword that once belonged to the Emperor Meiji and was used to behead leaders of the Satsuma Rebellion in 1877.

Hardly has Williams handed over the $2.3-million check, however, when Masao (Cricket) Kimura, a Yakuza thug, bursts in, steals the sword and decapitates the old Japanese collector from whom she bought it. Not for the last time in the novel, Williams barely escapes with her life.

Her troubles multiply. She can’t retrieve the check because the Japanese collector endorsed it and it belongs to his estate. The American collector gives her two weeks to recover the sword before he sues her and wipes out her business.

And even though Takeo (Tak) Saji, the Tokyo Metropolitan Police detective assigned to the case, is bright and honest, has “a lean face with a squared-off jaw . . . wide shoulders, an absurdly narrow waist . . . and a smooth, athletic way of walking,” he gets conspicuously little help from his fellow cops.

Two reasons, Saji tells Williams: He spent years in the United States and has become a misfit in Japan; worse, he is a burakumin, a member of a minority group subject to centuries-old prejudice.

Another complication: Saji owes his UCLA education and his job to the father of Hideki Kohno, the defendant in a coming investment fraud trial. Kohno fronted for a Yakuza boss and a former government minister, who fear exposure. They conspired to have several investors murdered in order to scare the others into dropping their lawsuit.

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Since the Japanese collector was one of the plaintiffs, his death is only the first on the Yakuza’s list. Armed with the sword (and warming to the delusion that he is a reincarnation of ancient samurai), Cricket Kimura stalks his remaining prey across Tokyo, whacking off appendages left and right.

Do we need to say that plenty of double-crosses follow, and that not all of Saji’s colleagues are free of gangster ties? That the “sexual Disneyland” aspect of Tokyo is fully exploited? That Saji and Williams wind up in the sack--er, futon? That her penchant for playing detective on her own only gets her into more hot water?

Blankenship (“Brotherly Love,” “Yukon Gold”) spent four years in Tokyo as an IBM executive. He marshals a lot of facts about Japan but fails to do more than skim the surface of that unique and enigmatic culture. His prose is basic at best; his sex scenes are hard to read without giggling.

The ostensible message of “The Time of the Cricket” is that “there’s a dark side to (Japanese) society.” Williams is warned: “The Yakuza has its hand in everything. Business. Government. The arts. And they’re very dangerous.”

But the real message may simply be that thrillers are much the same wherever they’re set--the same computers, cars and designer clothes; the same ruthless and venal people. At least Blankenship can’t be accused of Japan-bashing: His Americans, if anything, are even slimier.

Saji is a fairly interesting guy: hard-drinking, rumpled, gloomy, unwilling to be a burakumin role model because it’s un-Japanese to stand out in a crowd. Kimura, the killer, has imagination, unlike anyone else in the novel. Neither, though, can compete with the sword, which cuts off heads whose eyes “continued to blink” and leaves a man looking at “his own (severed) hand lying on the desk with the gun gripping it. . . . Pulling the trigger had been in his mind only.”