Just because clerks sell sex games doesn't mean that they necessary need to have had sex! An Akihabara erotic game shop has a part-time job listing for salesclerks. High school students aren't allowed, and prospective applicants need to be between 18 and 23 years old for the ¥850 ($US 8.46) an hour gig. The poster also points out:
We won't ask about inter-sexual experience!
Golly, that's awfully nice of them!
Virgins Welcomed [Akiba Blog]