Talk:初音ミク -Project DIVA- F Complete Collection/@comment-202.24.81.154-20190621130433

Does anyone know what the "special card" is for? I bought the limited edition set, and I can't seem to figure it out. The Amazon listing says it's for a bonus, so I thought maybe there was additional content you could unlock with the code on the back, but I can't find any information anywhere.