Yukko.. are you going to stay with a friend or in a hotel??? When I went to Japan last summer and stayed in a hotel for the first few days I was there, not many channels were available for the guest to watch. Also, my friend who I stayed with after didn't have that many channels.
Which comes to the conclusion, cable tv in Japan is very very expensive and not many people want to pay to have the service. Most families will only get the basic service (10-12 channels) for this reason. However, my friend could watch Music Station, Utaban, and Ayu Ready so you will have some coverage of JPop music while your over there.
