Home stays

I found two organizations that arrange homestays:
Japanese Association of the Experiment in International Living (EIL-JAPAN)
Pan Pacific Foundation (PPF)
I wrote them both but EIL-Japan does'nt allow me to study during the home stay and the PPF can't guarantee that I will be staying in Tokyo all the time - and that is where I want to go to school. If anybody knows of some other organizations that arrange home stays in Tokyo or nearby please let me know. I think I also will try to find private people that might be interested in having a foreigner living with them for a week or two.