One amazing phenomenon you will see in Japan is people waiting in lines for everything without any explicit instruction to do so. Sometimes it can make you wonder if Japanese culture somehow compels one find their place at the end of an orderly line. Unfortunately, in the train stations of Tokyo, an orderly line can quickly devolve into a shockingly physical game of musical chairs as soon as the car doors for the rapid express slide open.
On my own commute, there was a repeat offender who would always line up at the same time for the same train car as I would. His diminutive stature belied his assholish nature; every time I stood in front of him, I received a forearm shiver to the lumbar as soon as the train arrival chime rang. One day, as the train was pulling into the platform, I summoned all of my rage, turned my torso around, and looked him directly in his beady little eyes . I saw his eyes go from the empty seats on the train, to my angry gaze for a split second, then down to the ground. Lo and behold, when those doors opened, he politely filed into the car like a normal non-asshole. I now do this regularly (minus the rage summoning) and, save for extremely crowded trains, no one ever pushes their way into the car behind me.
TOKYO PROTIP: When waiting in line for a train, as the train is arriving, turn around and look the people behind you in the eyes to discourage them from pushing you into the train.