Exterior shots of the train were filmed on location on Japan, however, the interior shots were filmed on a set at Bridge Studios in Vancouver, B.C. The scenery rushing by outside the windows was simulated using large rotating drums with "blurred" scenery painted on it.
The many "hand to hand" weapons used in the film are fairly unique to Japan, to note a few.-Ninjato- The Ninjas primary weapon.-Shuriken- Commonly known as "Ninja Stars" they vary in design due to their use and from clan to clan with many groups having their signature design as seen in the film.-Manriki- A length of chain weighted at both ends, it was used to either ensnare or be used at distance to attack a foe.-Kusarigama- The chain and sickle, used to either keep distance with the weighted end or ensnare and dispatch foes with the blade.-Tanto- A short sword easily concealed and preferred in tight spaces.
The split toed footwear seen throughout the film most notably with the ninja are called Tabi. They are designed to accentuate the gripping power of the foot and provide better "ground feel".
While Takeda is speaking with Oshima about making a new sword, a Stellar's Jay can be heard in the background. Stellar's Jays are a bird found in North America, and are not found in Japan.
In one of the shots where Takeda and Racine spar (after Takeda receives his new sword), a camera man is clearly scene on the left edge of the shot. (at around 26 mins)
In the Opening scene where Racine is walking with his business partners talking about "selling ice to Eskimos", Racine enters the taxi-cab with his trench coat on. When he arrives at the hotel, he gets out of the cab without the trench coat. He leaves the hotel on a stretcher, still without the coat, but it appears again when he puts it on as he tries to leave the hospital.
Mieko:
Takeda is impressed Mr. Racine. No one has ever escaped the Makato, now you've done it twice.
Racine: Tell 'im it's not a skill I wish to continue practicing.