If i'm not mistaken Kiwami is the same engine as Yakuza 3-5, but slightly higher resolution on PS4's 1080p over PS3's 720p/1080i. Presuming you're at least in late 20s, do you really see much of a difference? I barely know between 30 and 60 FPS--has to dip below 20frames for me notice haha. Especially discerning interlace to progressive at 1080, the human eye literally cannot register enough stimuli to truly notice much, yeah?
Kiwami 2 on the other hand, I believe is Dragon. Yakuza 0 i can't recall at the moment; fairly certain also the 3-5 PS3 engine (especially because it was released on PS3 in Japan, whcich I'm so jealous of...)
Besides, by the time you get thru 0 and kiwami 2, remastered 3-5 should HOPEFULLY be localized on PS4...!