DLC Content Info :

– All In-game Rewards Unlock
– Original Costume Set

New Update Brings following changes that have matter for DLC All In-game Rewards Unlock:
– The Nightmare game mode
– The Inferno game mode
– Models
– Concept art
– The Shop*

All rewards which can be purchased in the Shop.

Note: Items purchased in the Shop will be placed in the in-game item box with the exception of the Hip Pouch which is placed a set location within the game.
You cannot use these items until game data has finished processing.
(Usage of costumes will remain unaffected)

* The shop is unlocked by completing the game’s story mode for the first time.
Players can use Points (P) to unlock new items and costumes.
Simply completing a challenge in the records will reward the players with points to spend.
The harder the challenges, the greater the points awarded.
Once acquired, all purchased items will be placed inside the Item Box for later use with the exception of Hip Pouches which will be placed in-game instead.
Note that Hip Pouches purchased cannot be used in the Assisted difficulty due to the latter exceeding the maximum Hip Pouches in-game.
* If a player purchases the All In-game Rewards Unlock DLC, they will unlock the shop and all of its items at once without needing to complete the game.

Credits to @Opoisso893 for help.