First thing to do when you arrive at Japan Expo Sud: going through security checks.
Attention, since last year, the entrance is set at Gate A at Marseille Chanot, where you'll find the security checks. You must go through there before joining the line corresponding to your ticket or leading to the cash desks.
Have a look at the new access map on this page.
Before going to Japan Expo Sud, read the list of forbidden and authorized items to avoid having your accessories confiscated.