My husband and I saw this in a anime store when we were biking home from the nearby town of Tamamura. We couldn’t open it, we weren’t going to buy it for about $16, and the guy in the store thought I was crazy for wanting a picture (when else am I going to see a CCG called Harem Master?). Based on where it was bought (and the surrounding objects), it’s most likely an adult themed hentai collectible card game. I wouldn’t let the cute little ghost fool you.
Porn? In my card game? It’s more likely than you think! :-0