Dragon Quest is having one of its biggest years in its 30 year history. Alongside of the July launch of Dragon Quest XI (in Japan), there's also a number of 30th anniversary celebrations on top of several recent re-releases.
One such event is the "Dragon Quest Summer Festival 2017," which will be held on August 5-6...in Japan. It's free to get in, but you'll have to pay 2,000 yen (roughly $17) to get access to its celebrity guests on the main stage.
If you're interested you can find tickets here if you want to attend at the Tokyo Big Sight venue. Say what you will about Square Enix, but they make a pretty big effort to constantly hold fan events like this, most of which seem to go over well.