Early-bird registration is extended to May 12th (JST)
April 27-May 6 is an extended holidy week due to enthronement events in Japan. Registration is accepted during this period but technical questions regarding registrations will not be answered till May 7th.
Plan your trip early. The end of the conference is at the beginning of a holiday season. Hotel rooms on Aug 9, 10 and 11, and seats on international return flights may sell out early.