The novel opens in contemporary Tokyo as John Rain (note the similarity to "John Wayne") follows a Japanese man whom he has been hired to assassinate. The target's file indicates a heart condition, so Rain shadows him into the subway and plants a tiny device on him to interfere with his pace-maker. As the poor guy has a fatal heart attack, Rain retrieves the device. Then he walks away. Murder disguised as death by natural causes: it is Rain's specialty.

Rain is a complicated guy born of a Japanese father and a white American mother, and feeling at home in neither country. As a youth, he volunteered to fight in Vietnam because he had multi-racial issues with which to grapple. Also he had manliness and "American-ness" to prove. Why sign on as a mere grunt when one can do the whole Airborne-Fort Bragg thing and be a Green Beret? Inevitably, Rain and his buddy Jake ended up in Military Assistance Command, Vietnam Studies and Observations Group. I know all about MACV-SOG; don't we all? This innocuous-sounding branch of the service performed the "Black Ops" that we've all heard hinted at in countless books and movies (though not so much nowadays): secret work in North Vietnam, Laos, and Cambodia.

Since then, Rain has lived in Japan, working as an assassin. He communicates by pay phone with his employers: he doesn't know them, and thinks they don't know him. He whacks his latest target, and all seems to be well. Until he meets the dead guy's alluring daughter Midori, an accomplished jazz pianist. Now the villains want to kill her. They think her father gave her an encrypted CD containing information needed by various conflicting government agencies. Smitten, Rain finds himself protecting Midori while hoping she won't realize that he murdered her father. Mutual attraction develops into an intense affair as they search for the missing disk together.

In Rain Fall, the author grapples with an unusual dilemma. He MUST make Rain a Vietnam veteran. In no other way can he explore the issues of Asian-American identity within military service. Plus the wars in Iraq cannot compare to Vietnam in terms offering that rich "Black Ops" territory that has infiltrated our pop-culture history. On the other hand, the author MUST set the story in the present day because the plot hinges on advanced technology such as cell phones, PCs, and the internet. So Rain ends up 49 or 50 years old at the youngest (when this book was written) – and Rain unexpectedly comes off as strikingly immature.

I mean, I could believe a disillusioned veteran choosing to be an assassin in 1975 when he's so young and unformed that his recent military experience dominates his entire outlook. But what kind of guy freezes himself into the narrow existence of a hit-man for two decades? A psychopath, of course, which Rain is too likable and introspective to be.

Rain has never gotten over his dark Vietnam secret: a cut-and-paste from the famous Vietnam War movie Apocalypse Now with buddy Jake taking the Colonel Kurtz role. It's impossible to shock people anymore with this scenario. I couldn't help thinking, Hmmmm. Jake wants to fight his own war against the communists, using his own troops (the indigenous Montagnards) and his own funds (from "the poppy"). Well, okay! Sounds like a win-win solution to reach U.S. military objectives while staying under budget. What's the problem with letting Jake do it?

Other characters highlight Rain's immaturity. Harry, a young Japanese hacker, helps Rain out of hero worship; the two interact like boys in their twenties. By contrast, Midori's wry dialogue makes Rain seem even more young and earnest in their romantic scenes. Furthermore, a spy and a cop who are both the same age as Rain have to spell out the plot complexities for him as he listens in wide-eyed wonder. He's a 49 year-old who seems like he's 28 at the oldest.

Not to hammer away at Rain Fall or anything. It's precisely because I find the book so good that its problems fascinate me. Rain and Midori and Harry are all strong characters, and the surveillance and assassination details are exciting and ring true – not to mention the fight scenes, drawn from the author's extensive knowledge of judo. The Vietnam stuff occupies a tiny fraction of the book. The strange naiveté of Rain is unintentional and can be overlooked.

The contemporary Japanese setting is where the book shines. Here, Tokyo is a dazzling city of many faces, poised on the cutting edge of technology and pop culture and fashion. You get precise glimpses of this particular hip jazz club or that specific elegant neighborhood until you feel that you have teleported to Japan and can see everything for yourself, the weird and exciting fusion of East and West and old and new, without dropping the fast pace even a fraction. Here, Tokyo feels as if it's defining the future of the rest of the world.

Not many books can immerse you so completely in so unusual a place; Rain Fall does so with exhilarating thoroughness and is well-worth reading. Rain Fall, the first book in a series, is available on Amazon through this link:

Rain Fall (John Rain Thrillers)