I meant to write this in my other post, but I don't necessarily agree that JAV agencies are all-out evil 'bloodsuckers' as jwlim80 pointed out. We can disagree on that one.
You gotta realize that most of these women don't know jack about getting jobs, few have any higher education, they are doing jobs that may even take an adverse mental toll, etc. JAV agencies do pretty much *everything* for them: They'll get them jobs of course, they'll drive them to and from the set, stay on the set during shooting, be there as emotional support, be there as financial responsibility support (set them up with accountants, etc.), help manage their social network presence, manage their fan clubs, be their all-out concierge even when not doing jobs, and more. Agencies sometimes even take extra precautions by creating pseudo-companies for each actress so she can keep her real life resume padded in case she decides to return to 'real work' in the future. Otherwise she may have unexplained blanks from when she was doing AV.
I definitely do think they still take too much percentage, but 10-15% as it's done in Hollywood may be too low given the amount of work JAV agencies do compared to their western non-adult counterparts ("here's a job! Go and good luck!").
good post Inertia
from their comments its clear they don't understand what agencies jobs are beside taking fee from their idols and forcing them to do AV