I can't find any reference to Josa as a Hungarian male name on the official Hungarian Names List (
http://www.origo.hu/utonevtar/index.html - in Hungarian but you can figure it out reasonably well - Keresztnév means '
Christian name', Becenév is roughly equivalent to 'nickname', Női név means 'female name' and Férfi név means 'male name').
I did find Józsa, which is essentially a Hungarian short form of
Josephine. But nothing resembling Josa more closely for that, for male or female.
I believe the Hungarian list is proscriptive (meaning, Hungarians naming their children can only use the names on the list) so at a glance it doesn't appear that Josa is a legit Hungarian name.
www.archaeochrisell.blogspot.com