*The difficulty system first used in [[Spring 2015 Event]] returns: you can choose between Operation A ({{lang|ja|甲}}, Hard), Operation B ({{lang|ja|乙}}, Medium), Operation C ({{lang|ja|丙}}, Easy) or Operation D ({{lang|ja|丁}}, Casual) . | *The difficulty system first used in [[Spring 2015 Event]] returns: you can choose between Operation A ({{lang|ja|甲}}, Hard), Operation B ({{lang|ja|乙}}, Medium), Operation C ({{lang|ja|丙}}, Easy) or Operation D ({{lang|ja|丁}}, Casual) . |