Where can I buy the locks

Most bicycles in Japan have this fancy rear wheel bike lock, which is very slick. I want to buy one, but can't find it anywhere. Thanks!

like the one shown on this page?

http://www.japan-guide.com/e/e2210.html

They can be bought at any bike shop, hardware store, or pretty much any store with a bike section. I've seen them at Muji, Don Kihote, and Tokyu hands for example.

Keep in mind that you can't make spare keys out of bike keys including the type of keys that usually come with these locks. It's just not technically possible, they say. So in the case of these locks, once you loose all the keys that were there in the first place, you're going to have to carry your bike to a bike shop and have the steel lock "sawed" off.

If you're going to buy a lock, it would be best to buy the type in which you lock using lock numbers. Of course, if you forget your lock number, that's a whole different story, but I always write it down and keep it in a special secret place.

Just to add...
Those locks are only a mild theft deterrent, as they can usually be removed fairly easily with a screwdriver. Cheaper ones can even be jogged open, as the locks are so puny. They are fine for locking your bike when you leave it outside the supermarket to go shopping, but most Japanese cyclists realize that you need a heftier lock and chain if you plan on parking your bike in front of a station all day.

"can usually be removed fairly easily with a screwdriver."

Now, why did they have to saw mine, I shall never know...

Uco,

Maybe some of the newer type are more substantial, but I know I have replaced an old lock on my bike, and it was simply a case of undoing the clamping screws and fitting a new one bought from the local "Home Centre".

Dave, my lock is dead gone and I'll never make the same mistake again, so this is just purely out of curiosity, but are you sure that these locks can be removed with a driver _even when it is locked_?

Because taking a second good look at the photo in the link Yllwsmrf provided us, I think you can (of course) take the screws off to replace your lock with something you like better, but eventually, you'll have to pull it off the wheel and that can only be done when there is a space for the wheel to go through, if you know what I mean.

In other words, you can take your lock off the bars, but as long as it's locked, you're gonna have to ride your bike with your lock always clinging to your wheel.

But still I agree with you when you say that you need one more separate chain or the like to secure your precious bike. I've seen my neighbor's handsome bicycle stolen and then returned somehow with most of the parts taken off.

Uco,

Ah, sorry, I was getting mixed up, so it's probably best to forget my comments.
If you lose your key with the bike locked, then it could well be necessary to saw the lock off. Having said that, I'm still sure my wife did this once, and I somehow managed to prise off the lock with brute force. Some of the locks on newer recent bikes are more secure though.

I'll keep that in mind, because I still use that type of lock, only with numbers instead of keys.

Just saw the cheapest versions of this type of lock on sale at Daiso for 315 yen.

Also had experiences with losing the key. Had to walk the bike to a bike shop to have it sawed off.

I agree that these are definitely just a mild deterrent. Still easy to steal the bike as it isn't locked to anything. Later unscrew the lock, remove the wheel and replace it.

Hey, thanks for all the info. My host stay family took to me to a bike shop (maybe called asahi) and I found what i was look for (and also a hello Kitty bell!). Thanks!