Tokyo Concerts & Sports?

Question:

Hi, I'm going to be in Tokyo from December 10- January 3, I REALLY need information about concerts or any events that I can attend. I am looking for everything interesting, fun. Especially musical concerts, although all of the ones I have found have seem to be sold out already. Are there any websites that are easy to access? They can be in Japanese or English.

I was also wondering about any popular sports matches. Will there be any good baseball or soccer games in December this year? I don't mind if they are not games, I want to see practice matches as well, if there is any way to meet the players. It also doesn't matter if I have to be in Japan to buy the tickets, I have relatives and can ask them to buy them for me.

Answer:

There is an ideal site for all the information about concerts, sports events and theatrical events.
This PIA site is the one but the problem with it is the language is not in English.
If you have relatives in Japan, you can ask them to get detail information for you from this site.