One of Japan's famous "Bullet Trains" is seen early in the movie. This is a 700 Series Shinkansen on the Tokaido line from Tokyo to Osaka. Its distinctive "duck bill" nose and tail design helps to reduce the air piston effect as the train enters tunnels at speed.
When Saito is lying on his back after being shot in the chest, something that looks like a squib is visible under his shirt. Someone mentioned first aid earlier in the scene, so it may be a bandage on his wound.