One thing that really surprised me about Japan is that most people only go out on Saturday nights. There was one instance I remember that perfectly exemplifies this. In late Spring I was out on a beautiful Friday night with some ladies walking around the Sakuragichou area. It's a great place to spend an evening with plenty of Izakaiyas, coffee shops, a nicely lit harbor area, and even a ferris wheel. Despite all of this, there was hardly anyone in sight.
When I asked why no one was out enjoying their weekend after a boring week of work, they didn't really have a good answer other than that's just the way it is. I suppose if you're going to be spending an extended period of time in Japan and want to meet people it's something to take into consideration.
