UPDATED November 14, 2011
Premium seats are available for purchase now. It is a lottery for the seats, so I don't think you can choose where you sit in the premium section. You can order them at eplus.jp here. There is also further information from eplus.jp here.
Thank you to Yuki for the links. :)
November 7, 2011
EMI Japan just announced that Libera will be having concerts there next April! Wow! So much advanced notice!
April 13, 2012 (Friday) at Orchard Hall at 7:00 p.m.
April 14, 2012 (Saturday) at Orchard Hall at 1:00 p.m.
Seating - 2150
Admission Tickets - Premium Seats ¥ 12,000 ($153.84)
Reserved Seats ¥ 8,000 ($102.56)
Casual Seats ¥ 3,000 ($38.46)
Premium seats - Available for purchase November 15 at noon through November 30 at 6:00 p.m. Includes premium performance benefits + brochure + front seat center area.
All other tickets - Available for purchase December 17.
More info here.
Thank you to Yuki for the information! :)