The dates must be posted somewhere since the ticketsale already started. At least there were infos about how to get fanclub tickets for the shows on the Backstage homepage.

Here are the dates that I found:

Sapporo Dome on Tuesday, April 18th, 2006
NAGOYA, JAPAN Wednesday, April 12th
OSAKA DOME ON APRIL 14TH AND 15TH, 2006.
Tokyo Done on Saturday, April 8th and
Sunday, April 9th, 2006