Yakuza...where to start?

So I ended up bying Judgment even though I haven't played a single Yakuza game. I like the game and the whole story around Yakuza is very interesting. I understand that Judgment introduced some new gameplay elements not present in other games but I'm still curious about the other games. What game should be my next game considering I only have a PS4? I can't play anything on PS2 or PS3 since I don't have them available.

Yakuza 0. Then Yakuza Kiwami 1 and 2

This.

This. Zero is the best place to start for newcomers, then just go in numerical order with the Kiwami remakes of 1 & 2.

If you by chance want more after Kiwami 2 , presumably remasters of 3-5 are coming to the west, but otherwise on the PS4 there's additionally Yakuza 6, Fist of the North Star: Lost Paradise (also made by the same studio), and if you're wiling to import, Yakuza Ishin (which is secretly maybe the best game in the series).

Thanks for the replies. I suspected as much, but it's good to get second opinions. I won't be importing anything myself, for various reasons. I guess I Will test out Zero when I'm done with Judgment.

This is the best answer.

And after you play all those games you could check out the Shenmue HD collection. Yakuza is considered a spiritual successor to the Shenmue series