"Bukkake" is an odd word, isn't it? Well, it's a Japanese word for the "act of splashing" as well as a kind of noodle. That's the origin of the word itself but in sexual terms, bukkake is much kinkier. Of course, it wouldn't be an original Japanese practice, if there weren't some kink involved, would it?
For those not in the know, the funny and sort of cute-sounding term actually describes the act of several men standing around a willing female and ejaculating on her. Usually, she is in a seated position, on her knees, or settled on her buttocks while they all jerk off around her.
Sometimes (and more often these days), the figure at the center can also be a man. This is quite prevalent in gay porn. Starting from the 1980s, the term defines a popular sub-genre of pornography and there are several moments of "money shot" or "cum shots" that occur.
As the act of an ejaculation orgy, essentially, circulated around Japan and migrated to the West, there started to emerge differences between the treatment of the subject. Humiliation and submissiveness was a strong part of the act itself.
And for those who love BDSM, this kind of public humiliation scene can be a huge turn-on
Since Japanese culture is more subdued, private, polite and conservative in public, it is customary to have the woman at the center be more submissively dressed. This means that sometimes she's dressed like a maid or a school girl.
Meanwhile, in Western culture, it's more prevalent to show the woman at the center actively and enthusiastically taking part in the arousal and stimulation of the circle of men, encouraging them and very much enjoying being the center of attention.
The term refers both to an act as well as the the act point of the scene and this is why, even though it's highly erotic, scenes will use this as a preface to a gangbang or an orgy. Many viewers find the filming of only the act not as engaging as a full sex scene.
In a way, the practice is a kind of group orgy or group domination with a single figure at the center being exposed to the power of those ejaculating on her (or him!).
For this reason, the practice itself has received a lot of negative criticism. Many women (and men) find the practice to be degrading and since it doesn't involve any sexual gratification on the receiver's side, feel that it borders on the non-consensual.
Despite this, there is an underground subculture devoted to viewing bukkake and, sometimes, those participating in real-life orgies can bring the practice to their own sexual games.