Of course, bicycles are found everywhere, and Japan is not the most bicycle-friendly place in the world. I do, though, think that the situation, at least here in Tokyo, is better than people imagine.
Now, I'm not talking about cycling, about road bikes or mountain bikes. I'm talking about biking in general.
Most of the bikes here are the heavy-duty tanks with a basket on front that are called mamacharis here (by the way, that is mama, for the typical housewife who rides the bikes, often with kids in the basket at the handlebars, to the market; chari is short for charinko, a cutesy word for bicycle). I have one, and all of my Japanese neighbors do, too. I, like my neighbors, use it for local trips, to the supermarket, conbini (convenience store), the dvd rental store, the train station.
It's something I never would have bought in the US, because I didn't see the need: clunky, ugly, heavy, and not particularly well-built. But I will have to get something like it when I get back. I do have a fast bike I use for commuting and exercise, but the mamachari is, like I said before, a tank, as well as a comfort. I'll give you an example of its "tankness": last year, a spoke broke on my commuting bike. I was late for work, and was really feeling energetic, so I decided to continue on and hope I could make it. About thirty minutes later, though, I heard another tinny "thwak", signaling a second broken spoke, and I knew I'd have to lock the bike up and scramble as fast as I could on foot to the train station (I leave early in case I run in to just this sort of problem). Good things come in threes (is that it?) and I broke a spoke on my tank very soon after. I immediately dealt with the commuter spokes, but I didn't really care about the tank; in any case, I suspected the tank could handle it. In truth, a year later I haven't repaired the tank spoke, and it still rides fine.
I mentioned above comfort, and I should probably explain that a bit. I ride my commuter at least three times a week to work. The saddle is up high and hard, the tires are pumped up as far they can go, and I've got clipless pedals; I don't feel comfortable riding it without gloves or a helmet. I usually lock it up, though I don't really need to. In other words, it is a bit of a hassle to ride for short trips. So the tank comes out at night for a trip locally. I would never ride it more than a couple of kilos, but it is set up perfectly for that La-Z-Boy feel: saddle way down and plush, bars bent back easily within reach, and soft tires that absorb every bump. When I ride the bike, even more than when I'm walking, I feel like I'm on a "stroll," waddling from side to side, not really paying attention to where I'm going, maybe even saying howdy to other folks on their charis (not really, but the impulse is there). That's what I mean by comfort.
The charis are built into the transportation system here (unlike the "cycling bikes," unfortunately). Again, this may be specific to Tokyo because the streets are winding and incomprehensible, but because of that winding incomprehensibility, cars usually stay off the back streets and stick to the monstrous-for-Japan-but-still-tiny-for-the-US main streets. So the back streets are left to strolling pedestrians and bicycles. On these back streets, you might forget that you are in the biggest city in the world, with their potted plants and their tottering old grandmas walking with tottering infants and their high-school punks riding side-by-side across the entire street. Bicycles even get to go down most one-way streets the wrong way, legally, with signs and everything to prove it. Oh, and they can ride on the sidewalk, something I avoid with my commuter, but that works well at the slow speed of the tank.
The main streets, of course, are another matter, and I won't deny I hate riding them. However, they beat the crap out of riding on any street in a big city in the US. Basically, it is for one reason: the drivers are polite. I'm not going to go into a big rant here about the idiotic phenomenon of road rage that seems to be an accepted part of life in many other countries because I said I wouldn't complain, but most of the time I can depend on drivers not to try to kill me to get to the next red light in time to stop. They do honk, but the funny thing is, they are usually honking not to tell me to get out of the way, but to make sure I know they are there (it took me a long while and a lot of my own road rage before I understood that). There are exceptions, of course, but most of the time...
Alright, obviously I could go on about the bike business for awhile, but I'll spare you. I'll leave you with this video about a bike park in Chiba (next to Tokyo). I've never been there, though it isn't far away; I may take a look some time before I leave. Anyway, it introduces the automated bike park there, but it also shows some of the everyday lifestyle in Tokyo (well, near Tokyo). Note: it is really, really loud.