Why are Japanese often late?

I realized that the trains in Japan are extremely punctual compared to other countries. Also, Japanaese people are always on time or a bit early when meeting up for business appointments.

However, for casual appointments, I believe that Japanese people are the least committed to be punctual. They break appointments half an hour or an hour before the decided time, or they don't even let you know at all that they cancelled. Does anyone here agree with my point of view.

It depends on the person!

I personally have not made the same experience as you. All my Japanese friends are always on time or at most a few minutes delayed. It is my non-Japanese friends here in Japan (from US, Canada and Taiwan), who tend to be much less punctual and reliable.

PandaDude,

Some do, some don't.
If you want to generalize for a whole population, then my experience differs from yours, as I find that Japanese people are generally more punctual and more likely to give advance notice of cancellations or delays than westerners.

It wasn't more of breaking the date in question... it was more of bringing up an appointment or important matter on a day where you can't have a say about it to change it. For example, my host family wanted my boyfriend to come along with them and me to Fujikyuu Highland. They said they would drive there from Yokosuka and pick him up from his host family on the way there. So He needed to know when to be ready. Two days before leaving, they told me to tell him to be ready to be picked up by 6 am.
Two days before leaving! (we changed the time to 7 am after inviting them to his host family's bar the next night and having a few drinks)
There were several other occasions when our group didn't know anything about certain situations... and right to almost the last minute we got informed. It was very frustrating at times. But nothing could be done.
I did have some girl friends be late before going out and having a good time, but it wasn't a big deal. I think punctuality in Japan is key only when it has to do with business or school. Otherwise, you can tell your friends a friendly "gomenne~~"

I think Miko's point is more about the Japanese host having the attitude of "Please leave all the planning in our hands, we will do the best arrangements we can for all of us" type of thing, which is a bit different from the original poster's case.

While I have not had any experiences of the sort mentioned by the original poster, and I do think that it depends on the person, but in there is any generalization to be made, I would say Japanese are on the punctual side.

Having said that, I have heard of behaviors among younger people (... this comment shows my age, huh? lol) not too concerned about being late to meet up with friends, etc., now that almost everyone has a mobile phone; you can simply call your friend waiting at the promised time still from a train thirty minutes away and say sorry! Mobile phones kinda make it easy to do that, because you know you have a way to reach your friend(s)...

Dota-kyan, last minute cancellation or no show, is considered very rude in Japan, and fortunately I have never encountered a Japanese doing this to me.

However, I truly hate to say that quite a few times, non-Japanese residents in Japan have done this to me (and they weren't always young). On the other hand, I do have read a post on the internet by a foreign resident in Japan claiming that their Japanse friends do this a lot (and these friends weren't young either). And I don't know why these things happen.

Anyway, if it's like you're having beer with two other friends and the third person doesn't show up, that's that as long as we know that the person is safe somewhere. If a person says, "I might come, but I might not." then that's that too. But if you keep someone waiting to start dinner, or if you make someone wonder if there's been an accident or not, that I think is universally very rude.

Japanese people are known for being on time. Most have puctual watches and are known for precision.

Generally, people who live in tropical, hot countries like Mexico, Spain, Philippines, etc. are known and expected to be late. That's because culturally it is acceptable or even fashionable to be late.