It seems that Sega has a bit of a kerfuffle on it's hands. After releasing the demo of Yakuza 6: The Song of Life on PSN, players found a way to use it to unlock the full game prior to its official release date.
The demo apparently was the full Yakuza 6 game and was designed to lock progression after completing the first chapter. The intent of approaching the demo this way was to allow players to make progress in the game in a way that would carry over to the full release if they made the leap to the fully priced game. While progress was indeed locked for users in regions around the world, that did not happen for certain players in North America. It's not clear if those players were able to tamper with the demo to break the lock or if it was simply never locked to begin with.
Whatever the case, Sega issued a statement via their social media channels to alert players that the demo would no longer be available in North America:
We apologize, but have had to remove the Yakuza 6: The Song of Life demo from the PlayStation Store. We are as upset as you are, and had hoped to have this demo available for everyone today. We discovered that some were able to use the demo to unlock the full game. We’re looking into the nature of the issue. Thank you for your patience.
It is unclear if Sega intends to re-release the demo at this time. Yakuza 6: The Song of Life is currently slated for an April 17 release date on the PlayStation 4.