蔵の中にあったもの is a Weiß Schwarz card from PRカード【Wサイド】 BD/WE42-P33. Compare listings from Singapore Weiß Schwarz sellers on CardJio, then jio them on WhatsApp.
Brainstorm Flip over 3 cards from the top of your deck, and put them into your waiting room. Choose a level X or lower character in your waiting room with 《Music》 or "Asuka(明日香)" in its card name, and return it to your hand. X is equal to the number of characters with 《Music》 or "Asuka(明日香)" in its card name revealed among those cards.