Yosuke and Yu hanging out. This Pass Card sticker was made by Riki/Liki of the Japanese Circle S2TK (煤竹).  We aren't sure of the exact date or place it was released, likely sold or given out at Comiket. 

What are they holding? Part of a Festival tradition perhaps?  Many people place stickers over their pass cards in Japan to hide personal details, or perhaps more risque artworks... You can find these cover art decals sporting a wide range of fan based focuses.
 

~This item qualifies for Lettermail super affordable shipping~!