[dirtyroboto]

With cultural activities the subject includes anything you would have to study in Japan. ie. Shinto or Japan specific Buddhism like Nichiren.
Other non religeous things will be Karate and Sumo and many other Japanese specific studies that cannot be undertaken in another country.

If you are of the religious bent and are studying a non Japanese specific religion then you may be required to state why you wish to study this religion in Japan.

If you want to be a Monk in Japan then expect to be valued less then an insect for the next many years of your life. This is only for Japanese, as if you are a gaijin then expect the life of an Amoeba to be your lot for a good few years.

In this time you will suffer the life of a monk. And good luck to you, as many Japanese cannot do this, and against their family's wishes they give up and find a new life elsewhere.

Being a monk in Japan is one of the hardest things you will ever do.
I wish you luck!