The Event Plaza is now known as the Exp Plaza!
The Exp Plaza is the place to be to walk in and have fun. From table top games to continuous activities like Cosplay Target, you can participate at any time for most of the activities. For others, such as card game competitions, you might have to sign up.
The main reason for this change is to distinguish between the scheduled activities of the Festival Events (lectures, workshops, etc) and the walk-in ones of the Exp Plaza.
So, the same Plaza, just with a new name.