"Non-Stop" opens with a simple but masterful scene that pumps the film full of instant tension without a word of dialogue or a single note of music on the soundtrack.

The scene begins in a Tokyo bank, focused on a quiet patron trying to be inconspicuous, sporting a baseball cap, sunglasses and a duffel bag. He keeps checking his watch. After two minutes he walks up to the counter and stands for another minute. Without any transaction taking place, he heads for the door and checks his watch again. It's clear soon enough that he's doing a dry run for a daring daylight heist.

Then the film cuts to a shot of this mysterious would-be robber's real life -- as a kowtowing kitchen peon in a restaurant, where he's consistently berated by the chefs and pretty much everyone else.

Suddenly his seemingly meticulous plan for the bank job reeks of desperation and foolhardiness, and a cloud of pent-up, insecure hostility forms over this mousy little man (Tomoro Taguchi).

The next day he returns to the bank, armed and ready -- but he's forgotten his mask, so he ducks into a convenience store to shoplift one. Within two minutes he's dropped his gun and fled as the clerk (Diamond Yukai) gives chase like a mad dog foaming at the mouth.

And for the rest of this exhausting, entertaining and relentlessly clever film, these two run and run and run, building a surprising story on kinetic energy and wild coincidence. The action jumps in and out of flashbacks to explain why its characters seem to forget the chase and just keep running for hours, into the night and on to the next day, no longer in a pursuit so much as a self-motivated marathon.

The robber, we come to realize, is running away more from his pathetic life than from the crazy clerk dashing after. The clerk, who it's revealed is hopped up on speed, is running away from his own failures -- he's a washed-up musician whose only just come to realize he's never going to be a rock star.

Soon he's running away from something more tangible, as well. When the two sprinters barrel through a crowded market, the clerk runs smack into a mobster (Shinichi Tsutsumi) to whom he owes drug money. The yakuza joins the chase, but like the others eventually his pursuit becomes a private escape as well. The night before, we learn in flashback, he failed to prevent a gangland hit that killed his boss and his mentor.

As the writer-director (who calls himself simply "Sabu") dips into the fantasies, memories and motivations of these three maniacal runners, he forms fascinating, interweaving backstories -- all of which converge in a parallel subplot about an overly gung-ho police taskforce mobilizing after the previous night's mob assassination.

"Non-Stop" doesn't aggressively exploit the humor of the circumstances it sets up, which is a shame because the movie is ripe with unplucked comedy. As it nears an indulgent, unexpected and exponential climax, a few glaring absurdities rear their ugly heads (propane tanks in a mafia headquarters?). But such qualms are not enough to dispel the entertainment value of a movie this original.