If sony is interested in growing its audience in Japan I would say that PlayStation 5 needs new IPs not follow ups from IPs they already have. Yes Final fantasy, monster hunter and more is a necessary base to stand on. However I don't see how these IPs will result in PS5 ending with a higher numbers than PS4.
If Sony is interested in Japan for the sake of market share in Japan they need new IPs that sell to the mass market in Japan.
I am not really sure if Sony cares or have the teams that can deliver the IPs they need.
Agreed. Why is nobody else seeming to mention this? Of course PS5 will likely get all the major sequels. Great, but that alone won't stop the decline given all these franchises are declining or flat at best in JP.
What new IPs or JP spinoffs did PS4 have? Most of the "newish" ideas came from the West, thus the sales growth of those titles.
PS4 sequels in JP
MH -> decline (in JP, Growth WW)
RE -> severe decline (nearly halved)
FF -> decline
DQ -> across plats (slight decline)
KH -> flat / slight decline
Yakuza -> decline
Persona -> growth
MGS -> decline (and retired)
Dark Souls -> flat
God Eater -> decline
Ace Combat -> growth
Nier -> growth (long gap between sequels I think?)
Gran Tourismo -> decline
Minna Golf -> decline
New Stuff
Judgment - new spinoff, did well
Spiderman - technically not "new", but nothing like it had really been done in a while. Did well
Death Stranding - hard to tell as a new IP, but it did retain some of the MGS audience
Code Vein - didn't seem to do that well as a spiritual successor to Dark Souls