Yakuza: Like a Dragon is getting paid DLC in Japan.
The Additional Challenge Expansion Pack has been announced for Yakuza: Like a Dragon and it contains New Game Plus and a higher difficulty mode, limited to a second playthrough.
According to the announcement (thanks, Gematsu), more information will be provided at a later date. We assume this means pricing, release date, and additional details.
Whether the content will also be paid DLC for the game's western release remains to be seen.
The game was released on PS4 in Japan on January 12 and will be available at some point later in the year in other regions.