How Does Diablo IV Couch Co-op Work?

Couch co-op is available on the console versions of Diablo IV, and the second player must log into their own console account to play as well as have the console account linked to their Battlenet. The second player's character data is saved to their Battle.net account, and in order to play those characters outside of couch co-op, they will need to purchase Diablo IV for that account.

Cosmetic items, such as those purchased from the in-game store, or obtained in special versions of the game, are only available on the account that purchases them.