Black Box Opening Campaign (神の箱(ブラックボックス)開封キャンペーン) is a special event to commemorate the release of Booster 12: Doll Princess of the Demonic Poison. Notably, this event was not announced in the official site. It was announced by individual shop instead. Player may obtain a special "Mikado Kurosaki" promotional card as the participation prize from this event. The promotional cards also comes as a "giant card" which is 4 times the size of a regular cards.