[RlUbQU3R]

You have a lot of cross-cultural experience, so I doubt content is going to be a problem. However as Kingofmyrrh mentions you need to proofread your english.

I would say drop phrases like this:

At first I was very impressed with all of the usual things that get a gaikokujin's attention....

Apart from the fact that the phrase is negative, it is bad english. Why are you mixing english and japanese in a sentence?
It is going to stand out to the reader that the only japanese words you use (in Romajii) are words to do with being foreign, gaijin, gaikokujin, nihonjin; however you also use the english word foreigner. Pick a language and be consistent.
You may be trying to show that you understand something about how (you think) the japanese see outsiders, but that is a loaded area that you don't need to draw attention to now. They are more interested in knowing about you, your experiences, and evidence that you are open-minded.

As Mingshi says don't accent the negative (that's a British education for you)

This is the only real classroom teaching experience I had...

"This gave me my first valuable experience of classroom teaching ....

I would agree with Mingshi that you should mention the positive organisational aspects of founding the kendo club now, don't hold back stuff for the interview, your job now is to get the interview, you can then think of stuff to expand on what you have said later.

Also as The great I AM is concerned, don't wear those arabian slippers with the curly toes or float into the interview on a magic carpet or mention that you know the Grand Vizier.... and no sudden movements.