As posted a few months ago, a new mini-set named Sun and Moon Strengthening Expansion Pack will be released in Japan on January 27th. The official Pokemon Card website has just revealed the set’s booster pack.
Like most concept pack sets, all of the cards in this mini-set will be holo. There will be 51 cards, some of which will be Sun & Moon reprints, but the rest will be brand new. Each booster pack will come with five holo cards, one of which is an Energy.
UPDATE: An image of the booster box has been released, showing art for Oricorio (Baile Style), Sudowoodo, and Mudsdale.