Extra items, Japanese audio
Although the DLC for Persona 5 will roll out in the coming weeks according to this schedule, you can grab some stuff for free now. That includes the healing item and skill card sets (read: boosts), a Japanese audio track, and a new difficulty called Merciless. Keep in mind that you can swap difficulties at any time in Persona 5.
Also live today is a series of costumes, themes, and avatars priced at $0.99 to $1.99, followed by extra costumes and BGM tunes, Personas, and avatar/theme sets on April 11. Having played the entire game without any DLC I can safely say you don’t need any of it — I’m just considering picking up a few of the Persona 3 and 4 homages for future playthroughs.
Persona 5 [PlayStation Store]