And those actors are the worst, at least, in my opinion. Can't stand any of them. There are better actors with slice of life themes (playing the brother, cousin, or a worker at an onsen) .
Those few ones have picked up some skills over their career, but they are still funny-looking actors, basically, the production house just want them to come in do their part in licking, kissing, molesting, use toys, get girl to suck them, they lick back, finger and the same list goes and get them to pop either inside or on their face.
Again there are much choices in Japan, I mean for a guy I would certainly like to play their part because less man to share for whole lot of girls that I can fuck and enjoy compared to European or American porn, where one actress can have thousands of male actors, while in Japan the same recycled male actors are almost always similar.