It is the sound of popping balloon if youguessing wht the name means. There are so many of these sounds then? Because in game you will have to pop quite a lot of different ballons! And doing so you will be to unlock more pictures at the local anime porn gallery. To unlock the image read the requirments of the winning, pick a round and begin to pop! Pay attention because these conditions may change from round to round. The only thing that doesn't switch is that for each round you will find a hentai picture added to a group as prize! And more about the collections - this game has a system of achievements in it which you will get for performing certain deeds thru the game. Will you manage to unlock all of them?