Poca or photocards
My money-sink of a hobby /j
Photocard is a piece of popular K-Pop merchandise. One or more photocards are usually included with each album which has made collecting them a popular hobby among fans. Since each album comes with numerous versions of photocards (normally at least one per group member) it is common for fans to sell and trade amongst each other. What photocards someone chooses to collect varies a lot between fans. Some will only collect photocards from a certain group or a specific member of that group. Others might collect photocards from a specific era of the group's career. Source