June 21st is the big day, and Gamania is hosting a "no wipe" beta. That doesn't mean you won't be dying during the beta but rather that you'll get to keep your characters and progression when the service goes live. Lucent Heart's open beta will also feature Q&A sessions with the game staff and GMs, community competitions including Grand Prix races and battle of the sexes events, and numerous opportunities to fight off invading monster hordes.
You can see the full event schedule at the official website, and don't forget to sign up for the open beta while you're at it. For more on Lucent Heart, see our first impressions as well as our coverage from this year's E3.