This is one side of Tokyo station. I walked all the way around Tokyo station. I also walked through Tokyo station. Getting through Tokyo station is not a simple task. The place is labyrinth. There is no shortage of coin lockers yet they are all full. If you find an empty one, your bag will not fit. This is how Tokyo station works.
I got better at navigating Tokyo station with practice but the place is colossal. I eventually lived in both Beijing and Shanghai. When I lived in Beijing I was a student living near campus so did not take the subway daily. I have however been on that subways system when it was busy and it is a lot bigger than it was in 2005. In Shanghai I did commute via subway going through their largest station every day for four years. Guangzhou and Shenzhen also have big subway systems, as do Paris, New York and London all of which I have visited. Tokyo is still the largest and this station likely the busiest.
If you like looking at pictures of Japan, the best of mine are on Flickr. If you want to read about my most recent trip to Japan that is on my blog.