GACKT Official news update. Translation below:

The sale of the tickets for 「GACKT 20th ANNIVERSARY -46th Birthday Concert-」have begun.
According to the venue’s specifications, the front nine rows will not be used, so on the tickets, the row listed as the tenth row will be the front row of this concert.

◆ Diamond seats
※From the front to the 5th row (10th row is the center) → Number on the ticket from 10th to 14th row (from the center up to 19th row)

Source: GACKT.com