Tokyo Events and Exhibitions  

Hi All,
need help. i am going to be in Tokyo for three days end of March - beg of April, i am trying to find websites with upcoming events / exhibitions/ shows or design museums - i should go see and check out.
so far no luck - with google etc

Live in Sydney, so its one of these chances to actually see some quality events and expo's while i am in tokyo. If you know of any websites or museums with upcoming events in tokyo, it would be highly appreciated. Thanks in advance!