From Starwars.com:

"General Tickets Sales Start May 18 in Japan, May 17 in the U.S.

Worldwide members of Hyperspace, the Official Star Wars Fan Club, and members of Index, a leading provider of content for Japanese cell phones, can shop early for limited, Premium tickets for Star Wars Celebration Japan, starting Sunday, April 20 in the U.S. (Monday, April 21 in Japan) in a special presale.

This presale event will run from 8:00 PM April 20 through 8:00 PM April 29, Pacific Daylight Time (PDT), which is 12:00 PM April 21 through 12:00 PM April 30 in Tokyo. Hyperspace members will receive an email with a special link to where they can purchase tickets early when the site goes live.

Not a member of Hyperspace? Join now at starwars.com/fanclub/ and take advantage of the best of Celebration Japan."

Click here for the rest of the post and info on ticket packages.